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Fedem Release 3.1.1 User's Guide

1. Fedem Release 5 0 User s Guide C 13 C FE Link Interface C 2 Nastran Bulk Data File format Nastran Bulk Data Conversion CWHD FORCE GRDSET GRID INCLUDE MATT MOMENT PBAR PBARL PBEAM PBEAML PBUSH PELAS PLOAD2 PLOAD4 PROD PSHELL PSOLID PWELD RBAR RBE2 RBE3 ASET ASET1 Comments See below See below See below Automatic definition of external nodes Same as ASET NOTE For the PBARL BPEAML entries Fedem currently supports the following cross section types see the MSC Nastran Reference guide for details ROD TUBE BAR BOX I and T Any other cross section types have to be manually replaced by equivalent PBAR PBEAM entries NOTE The shear modulus in the MAT1 bulk entry is only used by beam elements If the value on the Nastran file is zero for a MAT1 entry that is used by a beam element the shear modulus is automatically recomputed from the Young s modulus and Poisson s ratio through the formula G E 2 2 nu However if G 0 is desired for a beam element that is still possible by editing the ftl file created in the link DB directory when the model is saved NOTE If the Poisson s ratio in the MAT1 bulk entry is not given or is outside the valid range 0 0 5 but the shear modulus is given the Poisson s ratio will be derived from the Young s m
2. pomme H Q Command line mia Description Default value option pt fop Read output options from this file frsfile Name of results database file for mode shapes ftlout Name of link output file in FTL format gravfile Name of gravity force vector file help Print out this help text false licenseinfo Print out license information at startup false licensepath License file directory linkId Link base ID number 1 linkfile Name of link input file must be specified loadfile Name of load vector file lumpedmass Use lumped element mass matrices false massfile Name of mass matrix file neval Number of eigenvalues eigenvectors to 0 compute nevred Number of eigenvalues to compute for 12 reduced system ngen Number of generalized modes 0 printArray Additional debug print switch for certain 0 arrays rdbinc Increment number for the results data 1 base files resfile Name of result output file samfile Name of SAM data file singularityHandler Option on how to treat singular matrices 1 0 Abort on all occurring singularities 1 Suppress true zero pivots abort on reduced to zero pivots gt 1 Suppress all occurring singularities of any kind skylinesolver Use the skyline equation solver false sprMass Use the SPR equation solver for the mass true matrix when the GSF equation solver is used for the stiffness matrix sprSolver Use the SPR equation solver false stiffile
3. ea For efficiency reasons the number of matrix updates per time step should be as low as possible However if the increments in the input variables are large during a time step the system matrices need to be updated more often to ensure the nonlinear iterations converge You may choose between Fixed number of matrix updates or Variable number of matrix updates In either case you can also specify the Number of initial iterations with matrix updates and the Maximum sequential iterations with no matrix updates The first number defines how many iterations in the beginning of each time step should be performed with updated matrices If the iterations have not converged before reaching that number the subsequent iterations are performed with a matrix update frequency defined by the Maximum sequential iterations with no matrix updates However if Variable number of matrix updates is chosen a convergence based threshold is used in addition to determine when to do further system matrix updates The factor entered in Convergence tolerance factor for matrix updates is then multiplied with the active convergence 6 20 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis Es tolerances specified on the Tolerances tab The resulting tolerance is compared to the error norms corresponding to the active convergence tolerances and the matrices are updated as long as the error norm is higher than this toleranc
4. Fedem Release 5 0 User s Guide B 5 B Using the SWIFT Tyre Model B 6 B 2 Notation Table B 4 General Coefficients er Normalized Symbol Description Units with Gbvo Correction coefficient tangential belt stiffness qdEcx Brake force stiffness scaling coeffi cient Grcy Side force stiffness scaling coefficient QF 21 2 Vertical force coefficients Qkc1 2 Coefficients for tread element damp ing characteristics Creo Tire radius scaling coefficient Q Speed and load correction coefficient Qvi Tire growth coefficient qv2 Vertical force speed coefficient Table B 5 Displacements and Deflections er Normalized Symbol Description Units with Pbx Longitudinal belt displacement m Pox Normalized longitudinal belt displace Ro ment Poy Camber belt displacement rad Pbz Vertical belt displacement m Pp Normalized vertical belt displacement Ro Poy Normalized lateral belt displacement Ro Pho Wind up belt displacement rad Pry Yaw belt displacement rad p Dimensionless radial deflection PFz0 PFz0 Nominal tire deflection m p Normalized vertical tire deflection Ro B Using the SWIFT Tyre Model B 2 Notation SS A Table B 5 Displacements and Deflections Symbol Description Units b
5. Name an Soper il E Explanation PCy1 PCY1 Shape factor Cfy for lateral forces Ppy1 PDY1 Lateral friction Muy Ppy2 PDY2 Variation of friction Muy with load Ppy3 PDY3 Variation of friction Muy with squared camber PEy1 PEY1 Lateral curvature Efy at Fznom PEy2 PEY2 Variation of curvature Efy with load PEy3 PEY3 ES order camber dependency of curvature PEy4 PEYA Variation of curvature Efy with camber Pky1 PKY1 Maximum value of stiffness Kfy Fznom Pky2 PKY2 Load at which Kfy reaches maximum value Pky3 PKY3 Variation of Kfy Fznom with camber PHy1 PHY1 Horizontal shift Shy at Fznom Puy2 PHY2 Variation of shift Shy with load PHy3 PHY3 Variation of shift Shy with camber Pvy1 PVY1 Vertical shift in Svy Fz at Fznom Pvy2 PVY2 Variation of shift Svy Fz with load Pvy3 PVY3 Variation of shift Svy Fz with camber Pvy4 PVY4 eer of shift Svy Fz with camber and Fedem Release 5 0 User s Guide A 21 A Using the MF Tyre Model A 6 Steady State Magic Formula A 22 Formula Aligning Torque Pure Slip Figure A 11 Lateral Slip Condition Including Aligning Torque Pure Cornering M Mao Y F My t Fy M with the pneumatic trail t a D cos C arctan B a E B a arctan B a cos a a at Sp the residual torque M a D cos arctan B a cos a a at Sy Sup Sy t Spy Ky the scaled camber angle Ya Y Az with coefficients B t 455i qg 2df d3df e T 1Bz41z
6. 6 30 Stress recovery analysis 2 5452 deviate te agededlieeeee SUE EUER 6 31 6 6 1 Stress recovery OPTIONS sssrin e i cece cece eee een 6 31 6 6 2 Result output CONTIOL 6 cece ccc eee cence eee GS E ETA 6 32 6 6 3 Import of residual stresses from external analyses suus 6 32 6 6 4 Starting the analysis cece cee cece cence tence ene eneeeee 6 33 Mode shape recovery analySiS 0 ccc cece eee e eee e eee eeee 6 33 6 7 1 Mode shape Options 0c ccc c eee e nec e cee eere 6 33 6 7 2 Starting the analysis 0 cece cece cece ene 6 34 Strain rosette analysis duret e pere cid eed Mee ERES 6 35 6 8 1 Strain rosette options cc cece eee e teen eee eee cece seeeeeeee 6 35 6 8 2 Starting the analysis serrr nr eane cee cece een eee ee 6 36 6 8 3 Result OutpUt avesse dan ecenex ERE E KE HAODE E des EX SR vedo eda 6 36 6 8 4 Strain rosette definition file format 0 cece eee cee n eee eens 6 38 Strain coat alialy sisi od eso pus caut onde E egeun ag epi SAN HD a odas 6 40 Fedem Release 5 0 User s Guide 6 10 6 11 6 12 6 13 6 14 6 15 Chapter 7 7 1 72 6 9 1 Generating strain coat ccc cece eene 6 40 6 9 2 Strain coat analysis options ce cece eee cence eee ene en eens 6 41 6 9 3 Import of residual stresses from external analyses 06 6 42 6 9 4 Starting the analysis i c eae yews eee Yt ders Ye ees nen Pas 6 43 6 9 5 S
7. X Physicaltime Y Axial spring 3 Force value o X Physicaltime Y Axial spring 4 Force value Graphs can be set up before or after performing the dynamics simulation and other analyses If you create a graph before performing the simulation you can observe the values during the simulation as they are constantly updated see Section 6 11 Interaction during processing Otherwise you can view the entire set of graphed values after the simulation is complete Fedem Release 5 0 User s Guide 7 3 7 Postprocessing Results 7 2 Graphs Graphs plotting values vs time will have a time indicator bar present when a time history animation is loaded This bar will show the current animation time in the graph This makes it easy to see the correlation between the motion and the graphed values 7 2 1 Creating graphs and curves You can create as many graphs as you like either before or after solving the dynamics simulation It is recommended that you provide descriptive names for your graphs as the description is used in the Model Manager Results list to distinguish between graphs The description is also used as the title of the graph view when the graph is shown in the Modeler window To specify a description see Section 7 2 4 Graph properties below Once you have created a graph you will need to create curves plotted data for the graph and specify descriptions and properties for the curves There are two ways t
8. Se ee ee er i ee ee ee ea eS units UNITS LENGTH meter FORCE newton ANGLE radians MASS tkg TIME second B 28 B Using the SWIFT Tyre Model B 5 Tire Property File Example PC model MODEL PROPERTY FILE FORMAT SWIFT TYRE TYPE CAR FITTYP 221 USE MODE 24 MFSAFE1 52 80 MFSAFE2 zm MFSAFE3 150 LONGVL 16 667 VXLOW ah ROAD_INCREMENT 29 ROAD DIRECTION zo dimensions DIMENSION UNLOADED _ RADIUS 0 3135 WIDTH 0 205 ASPECT RATIO 20 6 RIM RADIUS 0 29 RIM_WIDTH 0 shape SHAPE radial width 1 0 0 0 esa e se Sess ae E ee ee ee eee eae inertia INERTIA MASS 9 3 I AY 0 109406207 I AXZ 0 0711140344 I BY 0 695823475 I BXZ 0 356664234 IR 0 0547031034 MA 0 23655914 M B 0 76344086 MR 0 107526882 C GRV 9 81 SSS SS SS Ss SS eS See contact_patch CONTACT_PATCH Q_A2 0 0353429027 Q A1 0 135228475 O LBF 1 Q LOS1 0 01 Fedem Release 5 0 User s Guide B 29 B Using the SWIFT Tyre Model B 5 Tire Property File Example Q LOS2 0 4 Q_LIMP1 0 8 Q LIMP2 0 0 QO KC1 0 106328549 Q KC2 6 6668 Q AMIN 0 3 FLT_A 2000 vertical VERTICA
9. 8 2 8 2 1 Result File Browser The Result File Browser can be used to view and manipulate files created by and used by the various Fedem modules It offers features such as enable and disable result files and delete individual results or classes of results It responds dynamically to any changes in the results data base and is kept up to date at all times The Result File Browser dialog Result File Browser Loader_saveAS1 fmm 5 i nmi xj File Last modified aj E Reduction EMI Front 0001 1 FEDEM Dynamics Solver o H WI 2 Boom 0001 Module version R4 2 i2 24 Sep 2007 09 11 52 Execution date 25 Sep 2007 15 03 10 E 3 Bucket 0001 GW 4 BellCrank 0001 5 WI 5 BucketLink 0001 E e Dynamics _ f Ell fedem solverfco 723 Bytes 25 09 2007 15 03 10 i E fedem_solver fop 190 Bytes 25 09 2007 15 03 10 i E fedem_solver fsi 40 3KB 25 09 2007 15 03 10 Executed on TOBAGO Windows NT x86 Family 15 Model 55 stepping User dagarild Storage requirement for system Newton matrix sparse matrix H velis Integer words 2328 9 1 KBytes Be p 3 frs 225KB Double precision words 7002 55 KBytes F PF th p uis 522 4 KB 25 09 2007 15 03 14 ABE s 2f 1 0MB 25092007 150314 oe MOnEL NUMMARY epRecovey 0000000000000 Up z 1 Front E 2 Boom Number of elements 9 H Number of nodes total 46 4 3 Bucket Number of external nodes 36 4 BellCrank Number of equations 166
10. H th_s_ frs eigval_ ev_p_ frs hub_ frs fedem_stress fco fedem_stress fop 11 hub fH timehist_rcy_ rod_ frs fedem_stress fco fedem_stress fop 2_rod_ hub 1 frs hub 2 frs mm fedem_modes fco 1_hub_ fedem_modes fop eigval_rcy_ rod_1 frs ec rod 2 frs fedem modes fco fedem modes fop hub frs rosette asc rosette _gage dac fedem_gage fco fedem_gage fop 2_rod_ 1_hub_ timehist_gage_rcy_ rod_ frs rosette asc rosette _gage dac fedem_gage fco fedem_gage fop 2_rod_ hub_ frs 1_hub_ hub_fpp_ fpp hub ftl m summary_rcy_ fedem_fpp fco fedem_fpp fop rod_ frs rod_fpp_ fpp rod ftl fedem fpp fco fedem fpp fop 2_rod_ dutycycle_rcy_ 1_hub_ hub frs 2_rod_ rod frs Fedem Release 5 0 User s Guide 8 Managing Results 8 3 RDB directory structure NENNEN 8 3 1 Link database The 2ink DB directory either specified as default link specific or model specific contains Fedem t1 files of all unique links imported into the Fedem model All t1 files in this directory are stored without external node information This reduces the total storage requirements A set of new subd
11. Iij Real Component i j of the sym metric point mass matrix PRBAR rid cni cn2 cml cm2 Parameter Value Type Description rid Integer Rigid bar property identifier cni cn2 Integer Component numbers of independent DOFs in the link coordinate system for the element at end 1 and 2 respectively cmi cm2 nteger Component numbers of dependent DOFs in the link coordinate system assigned by the element at end 1 and 2 respectively PRGD rid cm Parameter Value Type Description rid Integer Rigid body property identifier cm Integer Component numbers of the dependent DOFs in the link coordinate system at all slave nodes of the rigid element Fedem Release 5 0 User s Guide C 9 C FE Link Interface C 1 5 C 1 Fedem Technology Link format PWAVGM wid rc xi x6 wii win w21 w2n Parameter Value Type Description wid Integer Weighted averaged motion property identifier rc Integer Component numbers of the dependent DOFs at the slave node of the weighted average motion element xi Integer Row index into the weighting matrix for local DOF iat the slave node wij Real Weighting factor at master node j for the ele ment for all slave DOFs whose row index equals i VDETAIL vid visible Parameter Value Type Description vid Integer Visibility status identifier visible Bool Visibility flag visible 0means invisi
12. A Triads Copy Link Change Link Generate Strain Coat Sort by Name Wi Strain Rosettes Delete Del Strain Coat Summary FE Fatigue on link NOTE When running Strain Coat recovery on individual links or element groups a set of strain coat elements are automatically created on all shell and solid finite elements in the current selection unless such elements have been created in a previous run see also Section 6 9 5 Strain coat recovery on element groups or individual links Fedem Release 5 0 User s Guide 6 9 6 Mechanism Analysis 6 3 Model reduction 6 2 5 fedem_solver fedem_solver fedem_solver fedem_solver 2716 2716 2716 2716 6 3 NOTE Running FE Fatigue on element groups has the same effect as running FE Fatigue on the link s the groups belong to NOTE When solving on individual links or element groups the current settings in the corresponding solver setup dialog are used Viewing the progress of long duration analyses When solving a large model that takes a considerable amount of time it is often informative to know exactly how far in the simulation process we have reached at any time This can be done efficiently by viewing a res file that is continuously being written by the running solver in the Result File Browser see Section 8 2 Result File Browser When such a res file is selected the Info view is automatically scrolled to the bottom of the file and then con
13. Abbreviation Definition Units Ro Unloaded tire radius m Loaded tire radius m Re Effective tire radius m Tire cross section radius half tyre width m p Radial tire deflection m pd Dimensionless radial tire deflection LH Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 10 Definitions Table A 20 Tire Kinematics Definitions Abbreviation Definition Units PFz0 Radial tire deflection at nominal load m Mbelt Tire belt mass kg Q Rotational velocity of the wheel rads hy Distance wheel centre to road plane m Slip Quantities Table A 21 Slip Quantities Definitions Abbreviation Definition Units V Vehicle speed ms Vox Slip speed in x direction ms Vsy Slip speed in y direction ms Vs Resulting slip speed ms Vx Rolling speed in x direction ms Vy Lateral speed of tire contact center ms V Linear speed of rolling ms K Longitudinal slip oO Slip angle rad y Camber angle rad Fedem Release 5 0 User s Guide A 39 A Using the MF Tyre Model A 40 A 11 A 11 References Forces and Moments Table A 22 Force and Moment Definitions Abbreviation Definition Units Fz vertical wheel load N Fzo nominal rated load N df dimensionless vertical load EH Fy longitudinal force N Fy lateral force N F nominal load N My overturning c
14. Both types of spring and dampers have the same options and they will be described below The joint springs and dampers are accessed through Fedem Release 5 0 User s Guide 4 39 4 Mechanism Elements 4 7 Springs and Dampers the joint property panel see Section 4 4 2 Joint properties while the axial springs and dampers are separate items with 3D symbols and their own property panels 4 7 1 Spring properties The spring properties shown below consist of the following options Stress free length control Spring properties ee Lenath in model 1 1695298 7 OO000000e 009 A Initial stress free length 2 Scale None 5 X A 0 0 e f Initial deflection Stress free length change tin Cylinders Function e z 7 Stress free length angle control This group of options concerns the calculation of spring deflection The deflection is defined as positive when it is increasing the spring length Length Angle in model The current distance for translation or angle for rotation measured in the model as you have made it For joint springs this is the measured value of the joint DOF that the spring acts on For axial springs it is the distance between the two triads Initial stress free length angle Initial deflection These radio buttons and fields work together allowing you to introduce prestress in the spring by setting an initial stress free length angle different from the Length Angle in m
15. t1 files reduced matrix files etc is read from the link repository see Section 4 1 5 Using link repositories If the link repository is missing for example when a model file is moved Fedem uses the following search path to locate the links 1 The name and location of the originally imported FE link 2 The name of the original FE link located in a sub directory of the current model file directory with the same name as in the original FE file path only if the original path was an absolute path 3 The name of the original FE link located in a parallel directory of the current model file directory with the same name as in the original FE file path only if the original path was an absolute path 4 The name of the original FE link located in the same directory as the model file Fedem Release 5 0 User s Guide 2 Learning the Basics 2 8 Opening and saving model files 5 The base name of the original FE link with the extension ft1 located in the same directory as the model file 2 8 2 Saving models You can save the model using its current name and location or save a copy of the model using a different name and or location To save the model do one of the following gt To replace the current version on disk choose Save in the File menu or click on the save icon in the toolbar before writing the new file such that you can always go back the previously saved version by renaming that file in
16. 2000 4000 6000 8000 A 7 3 Effect of Camber Angle According to the W axis system an increase of the camber angle causes a decrease of the lateral force as shown in Figure A 16 Figure A 16 Tire Camber Angle and the Positive Direction of the Lateral Force According to the W Axis System Rear View A 34 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 8 Standard Tire Interface STI Ss A 7 4 Tire Model Output at Extreme Input Values At extreme large input values like a vertical load more than 3 times the nominal tire load a real physical tire might puncture or go to pieces In the tire model measures have been taken to avoid calculation errors or a computer simulation break down Depending on your simulation software the tire model warns the user when the input exceeds the validity range of the MF Dataset The tire property files generated by MF Tool contain maxima and minima values for the tire model input defining the validity range of the MF Dataset Fzmin and Fzmax for the vertical load F Alpmin and Alpmax for the slip angle a Cammin and Cammax for the camber angle g Kpumin and Kpumax for the longitudinal slip k In general the tire model fixes the B C D E and shift factors when exceeding the upper mentioned limits at the corresponding limit For vertical loads smaller than Fzmin the output of the tire model is equal to the output of the tire model for Fzmin propo
17. Controlling placement of temporary files Some of the Fedem solvers use temporary files during computations which are automatically deleted upon completion of the process On UNIX systems these files are placed in the directory pointed to by the environment variable TMPDIR if set If TMPDIR is not set or points to a non existing directory they are placed in the directory var tmp instead On Windows they are placed in the directory pointed to by the environment variable TMP if set If TMP is not set or points to a non existing directory they are placed in the directory C instead Fedem Release 5 0 User s Guide 6 5 6 Mechanism Analysis 6 2 Solver tools CAUTION Some of the temporary files may become very large for big models Make sure that the TMP or TMPDIR variable points to a directory with sufficient amount of free disk space 6 2 3 Additional solver options In the Additional Solver Options dialog advanced users can fine tune the behavior of the solver modules through options that are not available elsewhere from the respective setup dialogs or the various Property Editor panels Select Additional Solver Options from the Solve menu to open this dialog shown below fren C In each of the first six fields inixi you may enter text strings of Q command line options for the respective solver 1 module Refer to Appendix E press Recovery Command line options for a complete list of options for al
18. InitTransVel ux uy uz InitRotVel lt omegax gt lt omegay gt lt omegaz gt On Joint objects InitTXvel lt ux gt ZInitTYvel lt uy gt InitTZvel lt uz gt Fedem Release 5 0 User s Guide F 11 F Beta feature documentation F 12 Boundary conditions for dynamics analysis F 11 3 F 12 InitRXvel lt omegax gt InitRYvel lt omegay gt InitRZvel lt omegaz gt An InitTransVel specified on a link object will be applied to all triads attached to that link including the automatically generated center of gravity triad for generic parts This is overridden by a InitTransVel command on a triad object though The joint object commands will implicitly override the initial conditions defined on the slave triad of the joint if any NOTE If initial conditions have been defined both through traditional model file entries and description field commands the description field commands will be used Turning initial conditions off Sometimes during the creation of a complex model it is useful to test the dynamics when all initial conditions are off equal to zero To facilitate this without having to manually remove all the defined initial conditions in the model file the solver option ignoreIC may be used instead in the Additional Solver Options dialog Dynamics Solver field see Section 6 2 3 Additional solver options Then all defined initial conditions will be ignored assumed zero This op
19. It is also possible to move the reference plane by aligning it to a specified coordinate system in your model To do so use the Align CS or Align rotation commands See Section 3 5 2 Align CS and rotations Interactive Odometer and 3D Point Marker Many Fedem commands require you to selecta point 4 aca z in your model To help you locate specific points posa Fedem provides the Interactive Odometer and the 3D Point Marker shown at right These are displayed in liad the Modeler window each time you select a point The a odometer shows the coordinates of the selected point and the marker shows the location of the point in the Modeler window When using the Smart Move command to move or rotate links and other mechanism elements see Section 3 5 Moving mechanism elements the Interactive Odometer allows you to edit the selected point or enter a new 3D point using global or local coordinates The local coordinate system used is the coordinate system of the item you selected when the point was picked TIP You can use the Interactive Odometer with the Smart Move command to place a mechanism element link joint triad and so on at a point in free space The object can then be used as a reference when moving other objects To edit a point or enter a new point using the Interactive Odometer complete the following steps Fedem Release 5 0 User s Guide 3 5 3 Mechanism Modeling 3 3 Mechanism
20. false This is the default value on UNIX platforms On Windows the default is true Thus the default formatting of the DAC files will be suitable for the platform the recovery is run on Fedem Release 5 0 User s Guide E 17 E Command line options E 7 Strain coat recovery options fedem_fpp E 7 Strain coat recovery options fedem_fpp Command line er tion Default value option Descrip angleBins Number of bins in search for most popu 541 lar angle biAxialGate Gate value for the biaxiality calculation 10 blockSize Max number of elements processed 2000 together Bmatfile Name of B matrix file Bramsize In core size MB of displacement recov 1 ery matrix 0 Use the same as in the reducer 0 Store full matrix in core BufSizelnc Buffer increment size 20 consolemsg Output error messages to console false cwd Change working directory datacheck Do data check only exiting after data false input debug Debug print switch 0 double Save results in double precision false eigfile Name of eigenvector file fao Read additional options from this file fco Read calculation options from this file fop Read output options from this file fppfile Name of fpp output file frsfile Name of solver results database file fsifile Name of solver input file fedem solver fsi group List of element groups to do cal
21. 7 Postprocessing Results 7 3 Animations ss within an element for example top and bottom of a shell element or multiple deformation results on a node for example mode shape deformations for different eigenmodes Byoperation enabling this option consolidates the entire result set of the same type using the selected operation The options include Average Maximum Minimum Max Difference and so on Byname enabling this option allows you to load and display only the result sets with the specified name Complete links without such a result set will remain unchanged Parts of a link without the result set will be rendered gray Averaging These options allow you to enable or disable the averaging options If you select Do Average press the Opts button to define the properties in the Averaging Options dialog Average On Averaging on Node Averaging Options BEE calculates a single value for each Average on Element node in the FE model based on Zz x Werage operation yverage an the Average Operation and the ate niga Max shell Je 0 17 values specified in the Contour eph Average across element type Value settings Averaging on Element calculates a single value for each element in the same way Average operation allows you to Close select the averaging operation Average Max Min etc NOTE Element to Node and Node to Element averaging is not yet supported
22. Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions Limited ramp A tw L l Start Slope Ampl F i l L L L L L L Delay End Pulse y ff Width L cieli laus F i Ampl I Displace f ment L l l fi fi NI fi fi fi Position Fedem Release 5 0 User s Guide C Y vg ftv Ctk v vg vg v v Ctk v v v2v C offset start amplitude k slope Vg ramp start abcissa value delay v ramp end abcissa value end C vsv fy C A v lt v lt v 2 2 C vzv 2 C offset displacement A amplitude 6 width vo pulse center abcissa value position 4 59 4 Mechanism Elements 4 10 Functions Sine ftv A flv 2 Ct Asin2n fov 8 v amp v C Asin 2n fgv 0 v v Displace Fr ment C offset displacement A amplitude Jo frequency Hz q phase shift fraction of period v end of sinusoidal NOTE If the End value in a Sine function is specified less than or equal to zero that is interpreted as infinity Combined sine VvSv C A sin 2n f v 94 A sin 2n f v 8 Kv C A sin 2x fiv 0 A45sin 2n f5v 0 v v ftv C offset displacement Displace d A A amplitude f f frequency Hz q q phase shift fraction of period l ment 1 v end of sinusoidal NOTE If the End valu
23. Link properties Some of these options are discussed in further detail in the sub sections below Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 3 Model reduction 6 3 1 m 6 3 2 Starting the model reduction Model reduction is performed automatically for the links needing it when you start the dynamics simulation Fedem determines automatically which links need to be reduced based on the triad configuration and the connection to the rest of the model It also checks whether any of the settings in the Reduction Options tab that affects the results have been changed since the last reduction of that link You can also initiate the model reduction process manually at any time To do this simply click the Reduce All Links button on the Solvers toolbar or Solve menu You may also initiate the model reduction for only one or a selection of links by using the Link wise solving command see Section 6 2 4 Link and group wise solving NOTE If element calculations fail during model reduction due to bad element shapes etc all bad elements in the link are reported before the model reduction process exits NOTE Once a link is reduced that link will not be reduced again even if the Reduce All Links button is clicked again unless the link has been modified in the meantime by for instance adding or removing external nodes or altering the material properties Using component modes Fedem uses a Componen
24. One strain coat element is created for each Hide Element Faces non interior face of the finite elements in the current selection If a strain coat element already exist for a given face a new strain coat element is not created Therefore repeating the Generate Strain Coat command for the Generate Strain Coat k Solve Export Object same selection has no effect Sort by ID A 3 Sort by Name When creating strain coat elements by vum elete selecting an element group the new strain coat elements are automatically added to that group 6 40 Fedem Release 5 0 User s Guide 6 Mechanism Analysis p nq 6 9 Strain coat analysis If a link is selected the created strain coat elements are only added to the implicit element groups which the parent finite element belongs to not to any explicit element groups that the parent element might be a member of Refer to Section 4 2 Element groups to learn about implicit and explicit groups in Fedem NOTE The strain coat elements will appear in the ftl file in the link repository when the model is saved 6 9 2 b Strain coat analysis options To specify parameters for the strain coat analysis click the Strain Coat Recovery Summary Setup button on the Solvers toolbar or Solve menu You can specify the Start and Stop Time for strain coat recovery summary and the Time Increment to be used However if the Use all time steps option is enabled
25. Some Fedem commands such as Smart Move and Delete allow you to select several items at once To select more than one item press and hold down the Ctrl key and then click the items you want to add to your selection If you accidentally add the wrong object to the selection simply release the Ctrl key and click an empty space within the Modeler window The last selected item is deselected Selection history Fedem maintains a history of the items you select in the current session This history can be accessed using the Select Backward and Select Forward commands a gt To choose a previous selection press the Select Backward button You may need to press it several times to cycle back through the selections until the desired object or selection is reached Fedem Release 5 0 User s Guide 2 17 2 Learning the Basics 2 6 Executing commands NEM M ZEN gt To select a recent selection press the Select Forward button once or p as many times as necessary until the desired selection is reached Co located items Sometimes several items in a model are located very close together or on top of each other in Fedem these are called co located items To select a co located item click the same spot several times to cycle through the items Fedem cycles from the item closest to the viewer to the one furthest from the viewer Selection Filter Some Fedem commands allow you to select only certain types of items These restrictions are
26. You can select Lines Dots or Invisible from the Curve Type pull down list Curve Color Use the drop down menu to select a different curve color You may either select one of the pre defined colors or create a new by selecting more at the bottom of the drop down menu e Symbol type You can select a symbol cross circle or triangle etc to display on the curve Symbol Size Use the spin box to control the size of the symbols Num symbols Use the spin box to control the number of symbols 7 shown on the curve or select All to show a symbol on all points of the curve o NOTE The number of symbols entered is the maximum number of symbols shown on the curve However as symbols are only shown on existing data points there may be fewer symbols shown than requested 7 2 9 Curve Statistics On the Curve Statistics tab you can display different statistical properties of a curve The associated panel is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics Calculate Use scaled shifted Axis Domain Start fp 0 Stop fi 0 IV Entire Fedem Release 5 0 User s Guide 7 15 7 Postprocessing Results 7 2 Graphs eS o RMS The Root Mean Square value found from Mean The Mean value y e Std dev The Standard Deviation biased found from n 2 2 KM Q y g L where y is the mean n integral By the Trapezoid rule Q Max T
27. You may always animate the derived quantities as long you have recovered the stress strain tensors using the Operation menu in the Property Editor panel of the animation see Contours tab in Section 7 3 2 vou may enable direct export of a GLview Express VTF file with von Mises stress contours and optionally the deformed shape for further viewing in the Ceetron GLview environment see www ceetron com You may also need to specify the contour range to be used in the exported VTF file the max and min values of the exported von Mises stress will be used if no range is specified NOTE The deformation toggle in the Output Options frame also affects the GLview VTF export from the Stress Recovery The deformed shape will thus be exported to the VTF file only when this toggle is on None of the other toggles influence the VTF export 6 6 2 Result output control As explained above the Stress Recovery Setup panel may be used to specify the result types wanted as output from the stress analysis There are however some additional options for customizing the size and contents of the results database that may be specified in the Additional Solver Options dialog see Section 6 2 3 Additional solver options Some of these options are discussed below The complete list of options to the Stress Recovery solver module is found in Appendix E 4 Stress recovery options fedem stress Output accuracy By default the results from a stress r
28. or any other response quantity in order to simulate a wave event NOTE Simulating waves using a non constant sea level assumes that the cross section between the buoyant volume and the water surface is small compared with the wave length since the change in water surface normal is not accounted for 3 9 4 Gravitation The gravitation size and direction can be adjusted in the Model Preference dialog Remember to edit this in order to correspond to the units you are using The direction of the gravitation vector is displayed by the orange arrow in the lower left corner of the 3D modeler window shown at right 3 9 5 Initial translational velocity The complete mechanism can be given an initial translational velocity by entering a velocity vector in the Model Preferences dialog This velocity is distributed to all the Triads in the model This is useful if your event actually is describing the mechanism moving at some speed different from zero 3 26 Fedem Release 5 0 User s Guide 4 Mechanism Elements EE Chapter4 Mechanism Elements Now that you know how to create and assemble mechanism elements you need to know how Fedem defines the properties of elements and how you can customize them to suit your design requirements This chapter presents each of the mechanical and modeling elements used in Fedem mechanisms It also describes each element s properties and how they can be edited once the element is created Sections
29. B Ry Reference Global yy oo 2 Re b foo x B Y Additional boundary conditions apply to global directions z Used for initial equilibrium iterations only FF Node This area provides the number of the FE node to which the selected triad is attached and the triad s position in local link or global coordinates Additional Masses These options enable you to apply additional mass and inertia to the triad Fedem Release 5 0 User s Guide 4 19 4 Mechanism Elements 4 4 Joints Additional Boundary Conditions These options enable you to restrain the triad s movement during the initial equilibrium analysis and optionally in the eigenmode analysis See also Eigenmode tab in Section 6 5 1 and the Fedem R5 0 Theory Guide Section 7 8 Quasistatic equilibrium and Section 9 6 Eigenvalue results Origin This tab contains the Origin properties of the triad See Section 3 5 4 Origin property TIP The FE node number can be useful if you edit the link t1 file manually described in Appendix C FE Link Interface 44 Joints As with real mechanisms you connect each link to the others using joints A joint introduces motion and or spring constraints between the two links it is acting between These constraints are applied on the joint degrees of freedom Joint DOFs also called Joint Variables Each Fedem joint uses at least two triads to connect the joint to links One or more of th
30. Clickthe Create Generic Part button on the Mechanism Creation toolbar A Generic Part will be created with its origin in the global origin and with its centre of gravity in the geometric centre of the triads you selected 3 Setup the centre of gravity and mass properties of the link 4 Optionally add triads to the link by attaching them TIP You can at any time during modeling attach or detach new triads to the Generic Part See Section 3 6 Attaching and detaching elements Fedem Release 5 0 User s Guide 4 5 4 Mechanism Elements 4 1 Links 4 1 3 Copying links If you need to use the same FE model or Generic Part more than once you can duplicate an existing link by completing the following steps 1 Select the link you want to copy from the Modeler window or Model Manager Objects list rd 2 On the Edit menu select Copy Link The new link is placed offset from the original TIP You can also copy links using the shortcut menu in the Model Manager Objects list Right click the link you want to copy and select Copy Link from the shortcut menu The new link is placed offset from the original in the Modeler window 4 1 4 Link properties Links both FE Parts and Generic Parts are the basic components of any Fedem mechanism It is therefore essential to understand the link properties that are displayed in the Property Editor panel when you select a link TIP In addition to the settings found in the Property Editor p
31. E mod nu Young s modulus E mod and Poisson s ratio nu are used for computing the stress state at the rosette location 6 9 Strain coat analysis This analysis recovers the stresses and strains on all strain coat elements in the model and calculates a summary of the recovered results as it processes The output from the strain coat analysis is a result database file rs file for each link containing the maximums of certain stress strain quantities over the time interval considered Optionally you may also perform a rainflow and fatigue analysis based on the computed stress or strain histories during the strain coat recovery The result files from the strain coat analysis are created in separate directories for each link below the summary_rcy_ directory in the result file hierarchy see Section 8 3 RDB directory structure 6 9 1 Generating strain coat Before you run the strain coat analysis you Dbjects must generate strain coat elements for the links or element groups in question This is done by right clicking the links or groups in the Model Manager Objects list and selecting Generate Strain Coat from the menu Again multi selection is possible Results cu t Axial springs x F Functions Joints P Links 1 Front 2 Boom 4 Bell 8 Zoom To i B 5 Buc Create E IrLoads Bl Referenc x Strain i Show Element Faces H Triads Copy Link Change Link
32. FE models are generated in external CAE systems and stored in separate files that Fedem refers to as FE model files or link files Fedem stores link files in the Fedem Technology Link format f t1 and has import filters for the Nastran Bulk Data Format nas or bdf and the older Fedem Link Model format 1m This appendix describes these files and their formats Sections in this appendix address the following topics gt Fedem Technology Link format Nastran Bulk Data File format Fedem Release 5 0 User s Guide C 1 C FE Link Interface C2 C 1 C 1 1 C 1 Fedem Technology Link format Fedem Technology Link format In Release 2 5 Fedem Technology introduced the new ft1 file format for the definition of FE links This format is designed to be flexible powerful and extensible for adding new entries in the model The file is defined in ASCII format and can be easily edited using a text editor Syntax An ftl file contains a set of identifiers nodes elements control data and attributes and parameters that are expressed with the same overall syntax identifier id valuel valueN reference id text Name Description identifier Specifies field type e g element type attribute type id Unique ID for the field relative to the other fields with the same identifier valuel valueN Primary values for the object can be text integers or decimal digits references Additio
33. Firstly a triad in the element in question is noted to be connected to the link see also Section 4 3 Triads All the constraints loads etc that the element introduces will then be working on that particular link Secondly if the part is an FE model the triad is connected to the FE mesh of the part either by being directly associated with an existing FE node in the part or by using a Surface connector to distribute the forces in some way Fedem Release 5 0 User s Guide 3 15 3 Mechanism Modeling 3 6 Attaching and detaching elements When an element is attached it can generally not be moved relatively to the object it is attached to The Detach command is used to disconnect a mechanism element from the link it is attached to making it possible to move it around 3 6 1 Attaching using Attach The Attach command can be used when an element is to be connected to ground to a Generic Part or to an FE part with an existing FE node at the attach point To attach an item to a link or to the ground complete the following steps mis hs 1 Click the Attach button on the Mechanism Tools toolbar or select BI from the Mechanism menu The Guide panel prompts you to select a mechanism element to attach to the model Select the element in the Modeler window When you have made your selection press Done to confirm it The Guide panel then prompts you to select a link onto which to attach the object 4 Selecta link or the re
34. Force Moment value item under the joint variable node in question form the RDB selector see Selecting RDB results in Section 7 2 5 Curve properties Free Summary Origin Tz Rz m Constraint Type Rotation control f iied Angle in model 0 0 e Free C Prescribed C Spring Damper Load magnitude 3 js z 7 Load magnitude You can apply a Load on the joint variable This will be a torque or a force depending on whether the joint variable is a translational or a rotational DOF The actual force value will be saved 4 as a results quantity and thus available for plotting in a graph Length Angle in model This field shows the initial value of this joint variable as modeled The value defines the initial configuration of this joint variable in the dynamics simulation For rotational DOFs the value can be edited to set a different initial rotation The 3D view will then update instantly showing the new rotation in the joint symbol Prescribed Summary Origin Tz Rz Constraint Type Rotation control C Fixed Andel gle in model 0 0 C Free n gis Initial angle 0 0 C Spring Damper C Initial rotation po o Prescribed quantity Angle change Deflection 0 x None O z J Prescribed quantity You may choose whether you want to prescribe the Deflection the Velocity or the Acceleration for the joint DOF Length Angle in model This field shows the initial value
35. Note that you may multi select links in the Objects list to solve for two or more links simultaneously As always when trying to run the Reducer a link will only be reduced if necessary Group wise solving Solver processes that may be run on individual element groups are Stress recovery Strain Coat recovery and FE Fatigue A group wise solve process is started in a manner similar to that of a link wise process see Illustration to the right Right click the group for which you want to solve and then choose the wanted process Again multi selection is possible to solve for two or more groups simultaneously For further information on element groups refer to Section 4 2 Element groups bjects Results cu t Axial springs F Function definitions Joints Links E N Front 1 2 Boom K ch 4 Be 8 Zoom To ce 5 Be fftLoads e Refert amp Strain 2 Mo Triads p Copy Link Change Link Generate Strain Coat Export Object c Stresses B Strain Rosettes amp Strain Coat Summary Sort by ID Sort by Name FE Fatigue on link Delete Del Objects Results Axial springs x F Function definitions Joints amp Links amp 1 Front 2 Boom 3 Bucket amp 1 PTHICK 1 PMAT s Bel Cae 700m To i 6 5 Bucke Create AF X Loads Hide Element Faces W Reference E A Strain tose Show Element Faces
36. Software requireMeNnts cece cece cece e teen eene 2 2 Storing models and resultS cece cece cence e ene ence eens 2 3 2 3 1 FIEformatu iis bere PUT RN ere eda ous I IP RENS 2 3 2 3 2 ETC format veo STOP RM E NUI GN 2 3 2 3 3 Other supported formats 0 cece cece eee eee eee 2 4 Starting FOCI ys d ounere ene eee un eet Pes ade Sinise sae wares 2 4 Fedem Release 5 0 User s Guide iii 2 5 2 6 2 7 2 8 2 9 2 4 1 Template model file ccc cece cece cence erence eh 2 5 2 4 2 Console window cee cece cence hehe e hee ean 2 5 Touring the Interfaces cosa vr ear vC y E ERR a Xen Y eR 2 6 2 5 1 Fedem s main WiINdOW ccc e cece e cece ence cence eee nen een ences 2 6 2 5 2 Menus and toolbars cece cece cece erence ence cnet eee enen encase 2 7 2 5 3 Model Manager 0 cece cece cee n mH hehe emen 2 9 2 5 4 ID and Topology panel cesses 2 10 2 5 5 Property Editor ewer onse rete eene rede e vh eese vv desee se des 2 12 2 5 6 Workspace uci ier Ere ex PU NH TEES UL E ene aes 2 13 2 5 7 O tput LEist cL cL eR Ue ee EU ME Reg 2 16 Executing COMMANGS s eces ne was cest Cu Oo ER P E RONCRN E SOM ER 2 17 2 6 1 Selected editors erem detur ted bis etat bod aede one ione 2 17 2 6 2 DONE ee E 2 19 2 6 3 Cancel iss eee EU IR ARNAQUES 2 19 Visualizing the model 4 44 cet uec sd es eee ees ee es 2 19 2 7 1 3D Navigati n kse eese vts Sens ed taco eee te
37. and is able to export the reduced mass and stiffness matrix as binary files that may be imported into Fedem The advantage of doing the model reduction in Nastran is that you then have a broader range of element and material properties available for use on the link level such as orthotropic materials composites etc NOTE When the model reduction is performed in Nastran you also have to perform link level recovery in Nastran You can not perform Stress Recovery Mode Shape Recovery etc on a link that has been reduced in Nastran 6 4 1 Nastran DMAP The Nastran model reduction is performed using a DMAP script to facilitate the generation of the reduced matrices needed in Fedem A Nastran DMAP is a script program kind of API and programming language that modifies the execution of the Nastran solver The script is model independent and must be included in the Nastran bulk data file when Nastran reduction is desired The script called nastran dmap dat is located in the Template folder of the Fedem installation Refer to the Nastran documentation for further details on the DMAP script language 6 4 2 Nastran bulk data entries for CMS reduction In addition the entries describing the FE model the Nastran bulk data file must contain some additional entries when the link is going to be reduced in Nastran These entries are listed in the following Before the CEND keyword the following commands must be added to define the output files
38. assembly file s1dasm The names of the fedem models are assemblyname configuration name fmm A list of all the associated Fedem models of an assembly can be shown using the command List connected Fedem models The model file names of the connected Fedem models are saved along with the FedemSolid assembly file so you are advised to save the assembly model when you save a newly created Fedem model to keep the association alive 2 12 3 How parts and subassemblies translate to Fedem links A Fedem Link is one rigidly moving body in the dynamics model It is composed of all the parts and subassemblies that move as one rigid body 2 40 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 12 Using the CAD integration NENNEN When a Fedem model is created from an assembly one Link is created for each of the top level parts and for each subassembly marked to be Solved as Rigid Right click a subassembly and select the Component Properties command Solved as Rigid is the default setting for that property If it is set to Solved as Flexible Fedem creates Links from the parts and subassemblies inside the subassembly in question after the same pattern Top level parts and rigid subassemblies become Links while the flexible subassemblies are recursively traversed 2 12 4 Process communication B Fedem and FedemSolid are two executables that run side by side and communicates using COM When a Fedem command is ex
39. blocks used in Fedem have no editable parameters Each block is described below See also the Fedem R5 0 Theory Guide Section 8 4 1 Basic elements Comparator block The comparator block calculates and outputs the difference between the two input signals Adder block The Adder block adds the two input signals and outputs the sum Multiplier block The multiplier block multiplies the two input signals and outputs the product Fedem Release 5 0 User s Guide 5 Control System Modeling 5 3 Control blocks Ey 5 3 3 Integrator and limited derivator blocks Fedem supports the use of the integrator and limited derivator blocks described below See also the Fedem R5 0 Theory Guide Section 8 4 1 Basic elements EF Integrator block T The Integrator block outputs the integral of the input signal Derivator block The Derivator block outputs the derivative of the input signal within a specified bandwidth 5 3 4 Time dependent blocks The control system supports two time dependent control blocks described below See also the Fedem R5 0 Theory Guide Section 8 4 2 Time dependent elements Di Delay block BH The Delay block outputs a delayed input signal Sample and Hold block The Sample and Hold block outputs a sampled input signal 5 3 5 Non continuous blocks Non continuous control blocks are used for simulating nonlinear behavior They are used when the system response cannot be described by a li
40. item appearance 2 27 modeling 2 8 multiple selection 2 18 observing with Output List 2 16 pan F1 2 20 performing 2 17 print view 2 35 rotate F3 2 21 select dynamic center F4 2 21 3D viewing 2 22 zoom F2 2 20 comparator block 5 4 complex conjugate pole block 5 7 Component Mode Synthesis 6 2 6 11 component modes 6 11 calculating 6 11 connections stiff translating 4 31 triad 3 2 4 18 contact 4 36 Contact model for SWIFT Tyre B 19 Contact point C and normal load for MF Tyre A 7 control blocks control elements 5 4 about 5 4 controlling output 5 6 creating and manipulating 2 15 Control Creation toolbar 2 8 5 2 Control Editor 1 3 2 15 5 2 deleting blocks or connections 5 10 opening 2 15 5 2 Control menu 5 2 control module defining 5 7 control modules building 5 2 control system about 5 1 amplifiers supported 5 4 connection with mechanism 5 3 creating 5 2 diagram of 2 15 external 5 11 modeling 1 3 5 1 control system blocks adding lines 5 9 defining the module 5 9 editing properties 5 8 inserting 5 8 moving 5 8 removing breaking points 5 9 rotating 5 10 control toolbars 5 2 control tools 2 8 Control Tools toolbar 5 3 5 8 control servo systems 1 3 Coordinate system ISO described for tires A 5 coupling effects 1 3 Ctrl key using 3 21 curves exporting 2 35 2 36 Fedem Release 5 0 User s Guide modifying appearance 7 15 cut back 6 18 cyl
41. link data found in the link repository is consistent with the link file currently used Due to some rare numerical inconsistencies between reduced file data and the read link data file Fedem may signal that a link file needs reduction even though the reduced data are present CAUTION Do not enable the Ignore check sum test toggle unless you are sure that the reduced link data found on disk are compatible with the current model The consequence of using incompatible link data may be a diverging model or incorrect results A warning is issued whenever this toggle is enabled to stress this Expand mode shapes Enables the expansion of component mode shapes and free free mode shapes of the reduced link for subsequent visualization See Section 6 3 6 Visualization of eigenmode shapes from the model reduction and Section 7 3 Animations Eigenvalue Factorization Allows you to specify which matrix to be Choleski factorized during the eigenvalue analysis that is performed in the component modes computation Default is the mass matrix Recovery matrix storage precision Allows you to switch to Single precision storage of the recovery matrix a k a the B matrix on disk This will reduce the needed disk space for this matrix by 5096 and might be advantageous for very large links with many triads that will result in a big B matrix The default is to use Double precision storage QQ Reduced Needs reduction See Part tab above CAUTIO
42. moot Deformations enables display of link m id deformations scaled exaggerated by Max 2 000e 008 the Scale factor you specify Min fo NOTE This scale does not apply to the eigenmode Tick Marks deformations amp Count f7 C Spacing 2500 Q contour Legend these options enable you to customize the Contour Legend and how the result numbers are Close converted to colors Show Contour enables the display of contour contours on the mechanism during the animation Show Legend enables display of the Contour Legend bar in the Modeler window Colors the type of Color mapping used for the color contour e g Full Color or Red Blue See also Color mappings inSection 7 4 3 Mapping Linear divides color increments linearly and Log10 divides color increments on a logarithmic scale Look either Smooth or Discrete NOTE Discrete contours should only be selected when each face in the model has one single color for example when showing single element results or results averaged on elements Fedem Release 5 0 User s Guide 7 35 7 Postprocessing Results 7 36 7 4 3 7 4 Viewing animations Max Min you can set a maximum and minimum value to show on the Contour Legend See also Contour value domain control in Section 7 4 3 Tick Marks you can select Count number of ticks or Spacing difference between each tick mark and specify a val
43. optional Result files s ASCII results res nCode rainflow matrix file pp Duty Cycle nCode rainflow matrix file p Result files s Fedem GraphExp curve export utility Solver control files co fop fao Model file mm Results files s RPC time history data file rsp DAC time history files dac ASCII time history data files asc Fedem Release 5 0 User s Guide D 5 D File Types and Usage D 2 File usage for each program module D 6 Fedem Release 5 0 User s Guide E Command line options AppendixE Command line options Each of the Fedem programs may be run manually from a console window or using the Run option from the Start menu in Windows To facilitate such batch execution of the programs the complete list of command line options for each solver module is given in this appendix Any of these options may also be specified in the Additional Solver Options dialog see Section 6 2 3 Additional solver options The command line options may contain both upper case and lower case letters However the interpretation of the options is case insensitive For options accepting a numerical or text string value a character may optionally be added between the option and its value Thus all the following option specifications are equivalent myOption 1 0 myoption 1 0 MYOPTION 1 0 myOption 1 0 If you mis spell or
44. provides both a technology platform and an engineering framework for virtual testing of complex mechanical assemblies It provides a complete set of features to create solve and post process a model in a 3D graphical environment Dynamic results in the form of curves and animations are available during and after model solution Combined with the fast and numerically stable Fedem solvers the user interface facilitates an engineering process with shortened turnaround times and quick access to simulation results for a clearer understanding of the physical behavior of the model Fedem also provides intuitive and high performing postprocessing capabilities including full stress analysis eigenmode solutions strain gage solutions and fatigue analysis for selected time steps P FedemR4 2 K6 2 i01 fmm 7 E File Edit View Tools Mechanism Control Solve Result Windows Help DSHS wZWEBEHSmmSE IG amp eaaas cennjeoesuu a L amp wx QBS t AO F K 828 8 16 D D A A EJ Ed F3 Fl Ed ET E a ml d EB x Fedem R4 0 16 New Animation Time 0 4200 Time Steps All Step 42 t Fringes Von Mises Stress on Element node Average on Node 3 Base rotate Min Max 4123 989 1 996882e 008 4 Tool am Result set Absolute Max Def Scale 1 gay ur 1 1e 007 8
45. s n Position x from an imagined incremental rotation from the global Moe coordinate system axes to the orientation represented by E NES n x iotation Angle X the position matrix The bottom three items are similar Rotation Angle Y quantities computed from a Rodriguez parameterization Potation Anglez of the incremental rotation See the Fedem R5 0 Theory Guide Section 2 3 Finite Rotation for the definition of these angular quantities Results from the tire models When you have one or more tires in the mechanism model you may plot a variety ongitudinal slip of result quantities associated with each amber angle tire A few of these quantities the wheel sarah ita m carrier forces and tire energies are Tire deflection computed by the Fedem Dynamics Solver ena Lateral based on the tire model outputs All dial Longitudinal velocity remaining tire quantities listed in the ges Possible Results list for a tire are direct Closing velocity output from the tire models pde Wheel carrier local system Tire energy EE However not all of these quantities are available for all tire models supportedin Fedem Variables in the Tire characteristics ee ee ee group are available for MF Tyre only In the Tire deflection group only the Radial variable is available for all three models The remaining variables in this group are available for MF Tyre and SWIFT only Plotting internal contro
46. several other objects as well Fedem Release 5 0 User s Guide 4 Mechanism Elements es 4 10 Functions 4 10 1 Creating a function You create a function by right clicking acum qo an empty space in the Model Manager EEUU Objects list selecting Create and then Sort by ID I Damper characteristics aie Function You can also access the Sort by Name R Friction command from the Mechanism pull Delete Del F down menu in the main window menu fj Time history input file 4 Road elevation C External Control System E File Reference The new Function is automatically selected and its properties are shown in the Property Editor panel It will also be added to the list of Functions maintained in the Model Manager Objects list shown at right Objects Results ch Bi Axial dampers is Axial springs H E Control elements amp File references H R Frictions F Function definitions amp Bi Damper characteristics F Functions f Road elevations 4 10 2 Function properties When a function is selected in the Objects list its properties are displayed in the Property Editor panel shown below which is divided in three parts The left part contains fields for defining the function type and argument and the middle part contains a list of parameters associated with the chosen function type The right part contains two tabs one for displaying
47. timeEnd Stop time 0 timeInc Initial time increment 0 timeStart Start time 0 tolAccGen Max generalized acceleration tolerance on tolAccNorm Acceleration vector convergence toler 0 ance tolAccRot Max angular acceleration tolerance 0 tolAccTra Max acceleration tolerance 0c tolDispGen Max generalized DOF tolerance 0 tolDispNorm Displacement vector convergence toler 0 ance tolDistRot Max rotation tolerance go tolDispTra Max displacement tolerance 0 tolEigval Max acceptable relative error in eigen 1e 008 values tolEigvector Orthogonality limit for the eigenvectors 1e 008 tolEnerMax Max energy in a single DOF tolerance 0 tolEnerSum Energy norm convergence tolerance 0 tolFactCtrl Singularity criterion for the internal con 1e 012 trol system solver smaller value less restrictive tolFactDyn Linear solver singularity criterion for 1e 012 dynamics solver smaller value less restric tive tolFactorize Linear solver singularity criterion for initial 1e 009 equilibrium and eigenvalue analysis smaller value less restrictive Fedem Release 5 0 User s Guide E Command line options E 3 Dynamics solver options fedem_solver Command line option Description Default value tolInitEquil Convergence tolerance for initial equilib 0 001 rium iterations tolResGen Max residual generalized DOF force toler 0 ance tolResNorm Residual force vecto
48. while using default settings so are the secondary ones The output frequency of secondary variables however may be lowered by using the saveinc2 solver option saveinc2 Time between each save of secondary variables For models with an internal control system the saveinc2 option applies by default to control system data that is needed in a restart simulation as well see Time tab in Section 6 5 1 However it is possible to specify a separate output frequency for those data through the option saveinc4 Time between each save of control system data Output accuracy Primary variables are by default output in double precision 64 bit real However the output precision may be set to single by specifying the solver option double1 the appending minus sign indicates a false setting This will make the primary results file created by the Dynamics Solver half the normal in size double1 Save primary variables in single precision CAUTION You should not switch off double precision output for primary variables unless you are particularly low on disk space as this may affect the accuracy of the subsequent recovery runs This is particularly true for models experiencing large global displacements but small local deformations Secondary variables are by default output in single precision 32 bit real This is sufficient for most purposes and contributes to keeping the disk space needed by the secondary results file at a low
49. 0 User s Guide 6 Mechanism Analysis 6 3 Model reduction pc n1 eigenfrequencies are printed in Hertz The default value of this option is 12 for all links However the option is not effective for massless links For other links the option may be turned off by specifying nevred 0 6 3 6 X Visualization of eigenmode shapes from the model reduction To further verify the results of the reduction process and to increase the understanding of the link s dynamics properties it is often useful to visualize the computed mode shapes of the link This is possible if you toggle on Expand mode shapes in the Reduction Options tab of the Property Editor panel for the links in question before they are reduced see Section 4 1 4 Link properties Both the component mode shapes see Section 6 3 2 Using component modes and the mode shapes associated with the eigenvalues of the reduced system see Section 6 3 5 Eigenvalue analysis of the reduced links will then be computed during the model reduction and be subsequently available for viewing in an Eigenmode animation see Eigen Modes tab in Section 7 3 2 TIP It is particularly useful to study the mode shapes of the reduced system if you for instance get more than six modes with close to zero eigenfrequency That is usually due do an internal mechanism in the link caused by an error in the FE mesh and can be revealed when animating the corresponding mode shape TIP If you get less
50. 1 6 2 5 3 7 General transfer functions cece cece cece nee eee e ne ene ences 5 7 Building control modules cece cece cece ence nee enes 5 7 5 4 1 Setting Grid and Snap ivt pended v vede YE dae en 5 8 5 4 2 Insertingiblocks o teat wean yup Mee er ke E enia rc ER 5 8 5 4 3 Moving blocks s oi MA PD ERR 5 8 5 44 Editing block properties ccc cece cece cnet ene e ee en ene eenes 5 9 5 4 5 Connecting DIOCKS 2 252 cba cco vk i haces AREE e RE pheswua eae bs 5 9 5 4 6 Rotating blocks oe porre ede E RSEN AY DIA VUE 5 10 5 4 7 Deleting blocks or connections cece cece eee e ence ene eeees 5 10 External control systems sess 5 11 5 5 1 Requirements ccce es err ee ek s ta lene C E CERE C pet se 5 11 5 5 2 Data exchange iive velvet seta veu o ege oye deor ie ym dvd get 5 11 5 5 3 Connecting Simulink models esses 5 12 5 5 4 Performarice sive NES EUH pP ERIS 5 13 5 5 5 Limitations ever eeu a eens Arsene I Et alat nue ee ole 5 13 Mechanism Analysis Overview of Fedem analyses sss 6 2 6 1 1 Modelr d uction o ex e RA RIP RE NE RIA PAR 6 2 6 1 2 Dynamics analysis 0 0 ccc cece cece cnet eee eee een 6 2 6 1 3 Stress TeCcOVety ise oa Descr er tating eas oueeaure mane ee arabes EAR 6 4 6 1 4 Mode shape recovery isses ehe 6 4 6 1 5 Strain rosette recovery isses eee 6 4 6 1 6 Strain coat recovery issssssssssseeee ehem 6 4 6 1 7 Duty cycle a
51. 1 this is possible by entering the initial velocities directly 6 in the model file or through certain description field commands in the object property panel see Section F 11 Initial conditions for dynamics analysis for details If you do a static equilibrium analysis prior to the dynamics simulation any initial conditions specified will not affect the static equilibrium analysis itself However the subsequent dynamics simulation will then start from a configuration that is in static equilibrium but with a given non zero velocity state Modal analysis The dynamics analysis gives you the option of calculating the eigenmodes at different mechanism positions during the simulation These eigenmode solutions can then be used to expand the model s mode shapes for later use in animations See the Fedem R5 0 Theory Guide Section 9 6 Eigenvalue results for more information about the modal analysis To specify the parameters for modal analysis see Section 6 5 1 Dynamics Solver Setup Fedem Release 5 0 User s Guide 6 3 6 Mechanism Analysis 6 1 Overview of Fedem analyses 6 1 3 Stress recovery After performing the dynamics analysis a stress analysis can be conducted on the mechanism The stresses strains and elastic displacements can then be calculated at different time steps and or mechanism positions of the dynamics analysis See the Fedem R5 0 Theory Guide Section 9 4 Finite element stress analysis for more informati
52. 2 and avi formats Exporting a link To export a link complete the following steps 2 34 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 10 Printing and exporting 1 Right click the link in the Model Manager Objects list to access the shortcut menu Select Export Object to open the Save As dialog Specify a filename and location then click Save Exporting curves and graphs To export a curve complete the following steps 1 Select one or more curves in the Model Manager Results list and right click your mouse to access the shortcut menu Select Export Curves to open the Save As dialog Depending on your selection you will either be prompted for a file B name or a directory If you selected multiple curves the curve files will be named automatically Remember to select what file type you want to export to To export one or more graphs complete the following steps 1 Select one or more graphs or curves in the Model Manager Results list and right click your mouse to access the shortcut menu Select Export Graphs to open the Save As dialog If you have selected only one graph you will be prompted to supply a file name for the exported graph If you have selected several graphs you will be prompted to select a directory to export your graphs to In this case the graph files will be given names automatically For more detailed information on how to export and import curves and graphs s
53. 3 7 3 8 3 9 Chapter 4 vi 4 1 Moving mechanism elements e cece cece ete ee eeeenees 3 10 3 5 1 SMart MOVGz cic eek ves od teem dae wah ices eneak eeu Macs 3 10 3 5 2 Align CS and rotations 0 cece eee e nent me 3 12 3 5 3 MOVe TO Centet cscs eis asus Ere eme nep dl tore SC IE ROSE MR 3 12 3 5 4 Origin property ces centers E lE erre r PET E AES eden 3 13 Attaching and detaching elements lsuueuuslueusu 3 15 3 6 1 Attaching using Attach csse 3 16 3 6 2 Surface Connectors isses e meme eee 3 17 3 6 3 Surface connector commands 0 cece cece eee e tence ene eeees 3 18 3 6 4 Attachment rules and restrictions 6 ccc e eene 3 20 3 6 5 De tachingi reese tN a S EN uS S eS Ss US ON 3 21 3 6 6 Color of attached and unattached elements eeeeeeee ees 3 21 3 6 7 Invalid attachments ao cece cece cece cnet cnet nehmen 3 21 Deleting mechanism elements 0 cece eee e eee eeeenees 3 22 3 7 1 Deleting in the Modeler 0 cece cee n eect e teen cnet nene 3 22 3 7 2 Deleting in the Model Manager sss 3 22 Using file references in mechanism elements 3 23 Model preferences sssssssssesesseeee mn 3 24 3 9 1 Model database units 0 cece cence cence cnet ene e en enenees 3 25 3 9 2 Modeling tolerance 0c cece cece ence heme ran 3 25 3 9 3 BUOYANCY sincera course clad EE rate voiced EAA O
54. 5 0 User s Guide 8 Managing Results 8 2 Result File Browser NENNEN In addition to the full path to the imported FE data file and the internal repository file you will here also get a summary of some size parameters of the FE model for the link This includes the total number of degrees of freedom the number of nodes and the number elements of each type The number of triads attached to the link is also indicated The size information of the FE model is available also before the link is reduced It is therefore useful for assessing the computational cost of reducing the link This size information is not shown for Generic Parts even when a FE model is used for visualizing the link 8 2 2 Result manipulation The Result File Browser can be used to manipulate the results both enable disable results to decrease memory usage and delete single or multiple result files to save disk space Disabling and Enabling results To disable enable results select the files you want to enable disable right click and select either Enable Results or Disable Results from the menu The icons of the files immediately changes to reflect the current result state File Size Ex Reduction gt Dynamics Ej Recovery E 1 Front Ej Stress Recovery Front_1 frs 121 8 MB 3 14 04 12 Last modified fedem stress co O 3KB 5 15 2003 14 01 59 E fedem stressfop 0 2 KB 5 15 2003 14 01 59 i E fe
55. 7 32 Viewing ANIMAUONS so50 4 c 0h cottons couere weed swe beeteteeedie es 7 32 7 4 1 Play panel erre EILEEN M UNO MW 7 33 7 4 2 Animation controls diese Re geh eo pER EUH OE LI pr Ue idi 7 35 7 4 3 Contour legend Control ccc cece eee eect en eee nene 7 36 7 4 4 Exporting animations a sasssa ccc cece ccc cece eee eee a e eens 7 39 Managing Results Model and Result file handling ccc cece cece ete een eees 8 2 8 1 1 Discarding unsaved changes cece cence eee ene e eect en eeee 8 2 8 1 2 Saving a modeh orres I ee cs e ee n e bee ev RR heh Exe ens 8 2 Result File Browser rec Er ebbe Rr ane ek a d 8 3 Fedem Release 5 0 User s Guide 8 3 Appendix A Al A 2 A 3 A 4 A 5 A 6 8 2 1 The Result File Browser dialog cece cece cence nent en eeeenes 8 3 8 2 2 Result manipulation 0 cece e cece eee cece ene memet 8 5 8 2 3 Result files from restart simulations 0 cee cece cece eee e eee ee 8 7 RDB directory Structure cece cee cece eee e cere eene 8 8 8 3 1 l ink database ie LEER ete PE ode gale AREE Sake 8 9 8 3 2 Response directory Structure 0 esses 8 9 Using the MF Tyre Model About ME TW acct vorrei Pes d aA E waa A 2 MF T re Version 5 2 s veste cst d hand o OR eR nr te et A 2 Tire Road Interaction uu as oa Te Ex coa Eyed ta ea d dus A 3 Axis Systems and Definitions lessen A 5 AA 1 WAxis Systetm viscera ae neret esa pea E Rn
56. 723 Bytes 02 07 2008 09 26 23 1 Opening RDB file timehist sec O001Vth amp 4 fr amp E fedem solverfop 219 Bytes 02 07 2008 09 26 23 Header size 6678 Bytes B Data per step 6652 Bytes E fedem solverisi 37 1 KB 02 07 2008 09 26 23 mdr edis rice E fedem solverres 40 7 KB 02 07 2008 09 26 32 Opening RDB file eigval_0001 ev_p_5 fre fedem solver 1 fco 639 Bytes 03 04 2009 17 55 44 pa pus gt aa id rin fedem solvet 1 fop 261 Bytes 03 04 2009 17 55 44 WisPeconime Gr D Bytes 09 17 55 55 Reading results file timehist prim O001Vth p 1 frs 2 ae ie 5 xc Reading results file timehist sec ODDlVth s 2 fra ev p 5 frs t Bri p diis 522 3 KB 02 07 2008 09 26 32 A th_p_3tts 391 0 KB 03 04 2009 17 55 55 iri s 2s 1 0MB 02 07 2008 08 26 32 Po th_s_4 frs 662 6 KB 03 04 2009 17 55 55 m Recovery Close Simulation is restarted from step 100 time 1 000008 00 using data from previous time step 99 time 9 90000z 01 NOTE There will always be only one fedem_solver fsi file in the File list regardless of whether results have been performed or not because the same file is used by all restart runs This file only contains model data that is not allowed to change in a restart You may Enable Disable and Delete individual files from restarts in a similar way as the files from the original run see Section 8 2 2 Result manipulation in order to control what results should be active for further post processing and
57. Data Fourier Analysis Scale and Shi e Curve LO roig D Source X Axis O Axis From RDB Physical time Strain rosette 10 Gage 3 Gage stress From file C Intemal function 7 z a Edit None jo Edit None Complete QO Export curve automatically Description this is used as the name for the curve in the Model Manager Results list The description is updated automatically when changing the x or y axis definitions unless it has been edited manually in the mean time This name is not used in the graph view T TIP If you have manually edited the description field of a curve you can at any time return to the auto generated description by deleting it completely Legend if you choose not to supply a name for the curve you can enable Auto Legend to use a combination of the x and y axis labels for the legend When Auto Legend is used the legend will be always be equal to the auto generated description of the curve NOTE The Legend option must be enabled in the Graph Property Editor to display the legend in the graph view see Section 7 2 4 Graph properties above e From RDB From file Internal function the data plotted in a curve originates from either the results database RDB an external file DAC ASCII or RPCIII or an internal Fedem function The panel shown above is that of a From RDB curve The panels of the From file and the Internal function curves are discussed below
58. Fedem model 2 42 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 12 Using the CAD integration i About Fedem Add in This command provides version information and information on how and where the Fedem executable is found 2 12 6 Commands in Fedem Qu Connect to CAD system This command starts the available CAD system if it is not running If it is it connects the current Fedem session to the running instance of the CAD system eZ Open associated CAD assembly B This command does the same as the Connect to CAD system command but in addition it opens and activates the CAD assembly model that is associated with the current Fedem model Fedem Release 5 0 User s Guide 2 43 2 Learning the Basics 2 12 Using the CAD integration 2 44 Fedem Release 5 0 User s Guide 3 Mechanism Modeling Chapter3 Mechanism Modeling Now that you have been introduced to Fedem s user interface you can begin the modeling process This chapter describes how to perform the various commands you need to build mechanism models such as creating moving attaching and detaching elements It also describes how to apply motion constraints to the model Fedem s mechanism elements links triads joints sensors and so on and their properties are discussed in detail in Chapter 4 Mechanism Elements EJ Sections in this chapter address the following topics Basic assembling techniques Mechanism modeling environment
59. Guide Chapter 3 Model Reduction During simulation a triad must move rigidly in translation and rotation with the FE node to which it is attached This means that triads and therefore connections can only be placed on FE nodes with six degrees of freedom DOFs since three DOF solid nodes allow random rotation Triads in joints Triads are used to connect joints to links in the model in the same way that a door hinge uses one hinge plate to attach the hinge to the door and the other to attach the hinge to the frame Each type of joint may use a different number of triads to make the required connections When a joint is created its triads are created along and positioned automatically See Section 4 4 Joints for more information about how triads are used in joints Triad symbols Because triads can be used for several different purposes building blocks for joints attachment points for springs dampers and loads and measuring points for sensors different symbol is used to visualize the triads based on its usage TIP When attached all triads are the same color regardless of the symbol used to represent them To identify a triad simply look for the triad color default green Click the General Appearance button to access options for changing the color of triads and other mechanism elements Diamond A triad is depicted as a small diamond shown at right when the triad s coordinate system is not used in your
60. Joint This command can also be applied to the Cam Joint when the alternative master slave based formulation is used see Section F 1 7 Cam Joint below Cam Joint The default cam formulation uses non linear springs to model contact forces between the follower slave triad and the master triads along the cam curve This formulation has independent DOFs at the follower and all master triads and is able to handle large separation between cam and follower An alternative formulation in which the motion of the follower is expressed in a curvilinear coordinate system surrounding the cam surface and the slave triad is treated more like a true slave of the master triads is obtained by entering the following command in the description field Fedem Release 5 0 User s Guide F Beta feature documentation F 2 Links es MasterSlaveCam With this formulation one can also enter one or both of the commands FixX FixY The joint DOFs in these directions are then eliminated along with the joint springs and dampers and the follower is restricted to follow the cam in that direction Using these options can give a numerically more stable formulation when no separation between the cam and follower is expected or possible The master slave cam formulation is only able to handle small separation relative to the cam segment radius between follower and cam surface A cam surface with corners can also cause problems with this alternative form
61. MC F 7 DI cfte em F 7 ROS sec darse sep dan hd a rlep atacan t eral aspera F 8 AcdcditionaliTiasses s uc ce ee rere eth XO HC HRS Oe F 8 SENSO tics tscdeSociseuties te boocsuus Peri chocs eus ensse tube Tutor F 9 Generic database objects sss F 9 Prescribed Triad motion 2460 or EE re re F 10 Initial conditions for dynamics analysis ecee ence eee F 10 F 11 1 Initial velocities in the model file cece cece cece eese F 11 F 11 2 Initial velocities using description field commands F 11 F 11 3 Turning initial conditions off esses F 12 Boundary conditions for dynamics analysis usus F 12 Fedem Release 5 0 User s Guide Index Fedem Release 5 0 User s Guide xvii xviii Fedem Release 5 0 User s Guide 1 Introduction to Fedem es Chapter1 Introduction to Fedem Welcome to Fedem This chapter gives an overview of the Fedem program and its technological foundation It explains what a Fedem model is and outlines the different program modules Sections in this chapter address the following topics What is Fedem Non linear structural dynamics What is a Fedem model Control systems in mechanical analysis Using FE models CAD integration VVVYVYVVY Fedem solver modules Fedem Release 5 0 User s Guide 1 1 1 Introduction to Fedem 1 1 What is Fedem 1 1 What is Fedem Fedem an acronym for Finite Element Dynamics in Elastic Mechanisms
62. Name of stiffness matrix file terminal File unit number for terminal output 6 E 4 Fedem Release 5 0 User s Guide E Command line options E 2 Link reducer options fedem_reducer Command line Description Default value option tolEigval Max acceptable relative error in eigen 1e 008 values tolFactorize Equation solver singularity criterion 1e 012 smaller values are less restrictive The lowest value allowed is 1e 20 tolWAVGM Geometric tolerance for WAVGM elements 0 0001 version Print out program version false Fedem Release 5 0 User s Guide E 5 E Command line options E 3 Dynamics solver options fedem_solver E 3 E 6 Dynamics solver options fedem_solver Command line option Description Default value addBC_eigensolver Use additional BCs on eigensolver false allAccVars Output all acceleration variables false allAlgorVars Output all algorithm variables false allCGVars Output all centre of gravity variables false allControlVars Output all control variables false allDampCoeff Output all damper coefficients false allDamperVars Output all damper variables false allDefVars Output all deflection variables false allEnergyVars Output all energy quantities false allEngineVars Output all engine values false allForceVars Output all forc
63. Orientation Angle offset Deg 0 0 Edit reference direction v Use thickness from FE Mesh V Use material from FE Mesh Height 0 005 E Module Change side Poissons ratio fa 3 Layer position Material QO Rosette type Menu to select between different rosette configurations Single Gage Double gage 90 Triple Gage 60 and Triple Gage 45 Nodes This field displays the FE node numbers used by the strain gage The Edit button lets you select a different set of nodes Q Orientation The orientation of the strain rosette is calculated from a reference direction and an angle offset The reference direction can 4 be selected by pressing the Change reference direction button You can select either an edge or two points The angle offset is entered in the field as degrees o Layer position This is a feature that applies to strain rosettes on shell elements The strains and stresses will vary through the thickness of the shell elements with the extreme values on the top and bottom Normally when Use Thickness from FE Mesh is toggled the strains are calculated at either the top or bottom The Height field will then display the position of the strain rosette above the mid plane of the shell element e g half the thickness The Change side button can be used to switch the position of the strain rosette from one side to the other To calculate the strains and stresses at another level through the thickness of the shell elem
64. R5 0 Installation Guide Fedem Release 5 0 User s Guide 2 Learning the Basics 2 12 Using the CAD integration NENNEN 2 12 Using the CAD integration When Fedem is installed on Windows gt E it registers an add in with all the t Fedem Helps O CY ld supported CAD systems This add in New Fedem Model makes it possible for the CAD program Update Fedem Model and Fedem to communicate trough Open Fedem model the Fedem menu that is made available Cc in the CAD system This menu is shown in the picture to the right m Ug iw List connected Fedem models About Fedem Addin The supported CAD systems are all based on SolidWorks and they include the CAD editor add on to Fedem named FedemSolid Customize Menu In this section you will learn how to make use of the integration from the Fedem menu in the CAD system To learn how to use the CAD system itself you will have to refer to its own documentation The description below is for FedemSolid but it is valid for SolidWorks and NEiFusion as well 2 12 1 Overview FedemSolid and Fedem work together in order to easily create and update assembly based simulation models in Fedem Mass properties geometry positions and the assembly structure is extracted from the FedemSolid assembly and used to produce a starting point for a simulation model in Fedem There are two sets of commands that control the CAD integration features One set is in th
65. REX2 0 Fedem Release 5 0 User s Guide B 31 B Using the SWIFT Tyre Model B 5 Tire Property File Example RHX1 0 0066313 PTX1 1 PTX2 0 PTX3 0 overturning OVERTURNING COEFFICIENTS QSX1 0 QSX2 0 QSX3 0 MD LE MR lateral LATERAL COEFFICIENTS PEYI 1 1931 PDY1 0 99006 PDY2 0 14522 PDY3 11 231 PEY1 1 0026 PEY2 0 53683 PEY3 0 083107 PEY4 4 7866 PKY1 14 946 PKY2 2 1297 PKY3 0 028283 PHY1 0 0033518 PHY2 0 00053863 PHY3 0 07452 PVY1 0 044552 PVY2 0 023557 PVY3 0 53156 PVYA 0 03923 RBY1 6 461 RBY2 4 1957 RBY3 0 015164 RCY1 1 0812 REY1 0 REY2 0 RHY1 0 0086257 RHY2 0 RVY1 0 053266 RVY2 0 073458 RVY3 0 51728 RVYA 35 444 RVY5 1 9 RVY6 10 715 PTY1 1 PTY2 1 rolling resistance B 32 B Using the SWIFT Tyre Model B 5 Tire Property File Example ROLLING COEFFICIENTS QSY1 0 01 QSY2 0 OSY3 0 QSYA 0 aligning ALIGNING COEFFICIENTS QBZ1 8 9644 OBZ2 1 1064 QBZ3 0 8422 OBZA 0 QBZ5 0 22733 QBZ9 18 465 QBZ10 0 QCZ1 1 1805 QDZ1 0 099556 QDZ2 0 00074773 QDZ3 0 0065197 QDzZ4 13 053 QDZ6 0 0079448 QDZ7 0 00019609 QDZ8 0 29569 QDZ9 0 0089855 QEZ1 1 6085 QEZ2 0 35
66. Revolute Joint corresponding FE nodes Point to point joints are es Ball Joint found on the Mechanism Creation toolbar shown at eme right FE Rigid Joint amp Free Joint Each of the point to point joint types are described in the following Revolute joint respect to another about a common axis Its joint variable is the angle from the master triad to the slave triad about the common z axis defined by the right hand rule The Revolute joint has an optional Joint variable too i 4 namely the translation along the common z axis V Z translation DOF This Joint variable can be toggled on or off on the summary tab of the revolute joint property pane The revolute joint has a single DOF that allows rotation of one link with The symbol for a revolute joint is displayed in the Modeler window as shown below The arrow represents the slave triad and Z indicates the positive direction for the joint angle 2 The straight line labeled X represents the 9 master triad Q The revolute axis is the common z axis of the master and slave triads Together with the circle it represents the joint itself You can add friction to a revolute joint by selecting one from the list of frictions in your model in the Friction pull down list located on the Property Editor panel See also Section 4 6 Frictions and the Fedem R5 0 Theory Guide Section 6 5 Joint Friction Fedem Release 5 0 User s Guide 4 27 4 Mechanism Element
67. T EA Ye gt Fx d Fo lt y a Ve sx P M F body me I lt i slip forces and moment The forces and torque that are transmitted through residual springs from the contact patch to the Rigid Ring are given by Equations B 30 to B 32 Fo E ProF zo 2K Pkg B 30 i 6 Pryf z0 2k Prykig B 31 Myz PryCro 2 rg B 32 Transient Slip Behavior At change of slip it takes a certain distance to build up the forces in the contact area This transient behavior is incorporated in the model and is referred to as relaxation length The contact length is the main determining factor for the transient properties in the contact patch and it is a function of vertical load in accordance with Equation B 33 a edF qai F Ro B 33 The resulting function for the contact length is displayed in Figure B 12 on page B 18 The relaxation length in the contact area o is a function of the adhesion level m in accordance with Equation B 34 which is similar to Equation 3 28 in reference 2 o m a B 34 B 20 B Using the SWIFT Tyre Model B 3 Force Evaluation m T The value of m is also used in the so called Phase leading network that is applied in the aligning moment calculation see reference 2 In order to prevent numeric instability around zero slip when m approaches 1 the value is modified within a small band of slip as displayed in Figure B 15 Figure B 15 Modification of
68. The tangent plane is an accurate approximation of the road as long as the road radius of curvature is not too small that is not smaller than 2 meters Fedem Release 5 0 User s Guide A 7 A Using the MF Tyre Model A 4 Axis Systems and Definitions Figure A 4 Contact Point C Intersection Between Normal to Road Tangent and Wheel Plane ERN SCTNS SES es AKE Wey KOZ 4 The normal load F of the tire is calculated with F C p K p A 1 with p the tire deflection and p the deflection velocity of the tire Table A 3 Normal Load Name Name Used in Tire Property File Explanation Ro UNLOADED RADIUS Free tire radius Cz VERTICAL STIFFNESS Tire vertical stiffness Kz VERTICAL_DAMPING Tire vertical damping A 4 4 The Effective Tire Rolling Radius The loaded tire radius R which is defined by the distance of the wheel centre to the centre of tire contact see Figure A 5 The effective rolling radius R at free rolling of the tire is defined by R A 2 For radial tires the effective rolling radius decreases with increasing vertical load at low loads but around its nominal load the influence of the vertical load is small see Figure A 6 A 8 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 4 Axis Systems and Definitions When assuming a constant vertical tire stiffness C the radial tire deflection p can be calculated with A 3 o i OL N
69. This means that no contour colors will be shown when loading an animation with such settings Max shell average angle you can specify an angle above which the averaging between shells stops The angle is used as a tolerance when comparing the globalized coordinate systems of the elements in question Average across element type if enabled Fedem averages the contour values across element type borders Multiple Face Results This option enables you to specify the averaging behavior across elements that interface on a surface such as stacking of elements with the same size and shape but different thicknesses Fedem Release 5 0 User s Guide 7 27 7 Postprocessing Results 7 3 Animations TIP Contour data is only loaded for visible elements This means that you can select which of the multiple face results you want to show by hiding the appropriate elements Eigen Modes tab If you selected Eigen Mode as the animation type in the Property Editor panel you can animate the rigid body mode shapes calculated by Fedem while solving the dynamics If the Mode Shape Recovery analysis is performed it is also possible to include link deformations associated with the eigenmode in the animation You may also animate link mode shapes computed during the link reduction if the Expand mode shape toggle in the Reduction Options tab was on see Section 4 1 4 Link properties To animate mode shapes you must specify the se
70. a RR E elke A 5 A 4 2 Units o Eencex e REPEDU SEE TE E CER HERE nad avers ass eee A DRER A 6 A 4 3 TheContact Point C and the Normal Load 0 cee eee eee eeee A 7 A44 The Effective Tire Rolling Radius selle A 8 A45 Tire Slip Quantities oc ere ADU RED SU EET ONE DN N AE A 11 The Magic Formula Tire Model MF Tyre cceee cece ees A 11 A 5 1 Introduction icone ever reb EPIRI HAS ERST YA ey et A 11 A 5 2 History of the Magic Formula esses A 12 A 5 3 Learning the Basics of the Magic Formula lssseseeeesse A 13 A54 User Scaling Factors serere ccc cee cee cee e cence tent e A 15 Steady State Magic Formula cece eee e cece eee e eens A 18 A 6 1 Steady State Pure Slip 1 eee cece cece e nee e eee e teen aao A 18 A 6 2 Magic Formula Steady State Combined Slip sees eee ee A 25 A 63 Transient Behavior 0 cece cece cece een ene een cnet ene eenenens A 30 A 6 4 Transient Model Equations liess en A 30 A 65 The Gyroscopic Couple ssssssssesssee ee A 31 A 66 Switching from a Simple to a Complex Tire Model L A 32 Fedem Release 5 0 User s Guide xiii A 7 A 8 A 9 A 10 A 11 Appendix B xiv B 1 B 2 B 3 B 4 Some Practical Aspects o co eee Opera ata va e Fe RC A 33 A 7 1 Rolling Resistance TOrque 0 ccc cece cee nent eee menn A 33 A 7 2 Typical Tire Characteristics 00 cece
71. a large model This command is also available from the Topology view and the Model Manager see Section 2 5 3 Model Manager and Section 2 5 4 ID and Topology panel It is also applicable on Control Elements and Control Lines in the Control Editor view see Section 5 1 1 Control Editor Zoom Window To enlarge a rectangular area press the Zoom Window button The command can also be activated by pressing the Z key Zoom Window With Auto scale To enlarge a rectangular area press the Zoom Window With Auto scale button The contents will be auto scaled to fit the entire plotting area This command can also be activated by pressing the X key Zoom In To enlarge the active view by a predefined scale factor press the Zoom In button Zoom Out To reduce the active view by a predefined scale factor press the Zoom Out button Pan Left To move the active view to the left press the Pan Left button Pan Right To move the active view to the right press the Pan Right button Fedem Release 5 0 User s Guide 2 23 2 Learning the Basics 2 7 Visualizing the model Pan Up To move the active view up press the Pan Up button Pan Down Am To move the active view down press the Pan Down button 2 7 4 General Appearance The General Appearance command can be used to control which entities are displayed in the Modeler window This command also provides control of the size and appearance of mechanism symbols Click t
72. a toolbar Standard provides standard file operations such as Open Save Exit and selecting and deleting objects Fedem Release 5 0 User s Guide 2 7 2 Learning the Basics 2 5 Touring the interface 2 8 Windows provides commands for controlling the active window selection Modeler Control Editor Output List Result File Browser and hiding showing the Model Manager and Property Editor panels gt Zoom and Pan provides commands for zooming and panning the two dimensional display of graph views See Section 2 7 3 Zoom and Pan for more information about these commands 3DView Control includes commands for rotating the view and changing the view perspective in the Modeler window See Section 2 7 2 3D View controls for information about manipulating the view gt Solvers these commands are used to set up start and stop mechanism analyses and calculate specific results See Chapter 6 Mechanism Analysis for information about these commands Mechanism Creation contains commands for importing links and creating mechanism entities such as joints springs dampers forces and sensors see Chapter 4 Mechanism Elements Mechanism Tools provides commands used in modeling such as moving attaching copying objects and applying motion constraints See Chapter 4 Mechanism Elements for information about modeling tools gt Control Creation provides commands for creating control object
73. amp 5 BucketLink Number of generalized modes o Link Centre of Gravity 1 Front 4 70136E 01 4 11788E 09 6 432 2 Boom 1 92504E 00 2 97608s 09 6 492 A The File list Lists all relevant files from the Reduction Dynamics solver and Recovery processes The Info view Displays information about the selected file The File list The list is ordered chronologically with Reduction first then Dynamics and Recovery All directories will list the following file types if present frs Binary result files res Log file for the solver processes fco fop fao fsi Input files to the solver processes mx Reducer matrix files fsm Internal data structure files vVYYYY Y fpp fef Fatigue result files Fedem Release 5 0 User s Guide 8 3 8 Managing Results 8 2 Result File Browser 8 4 The files are listed with file name size and time of last modification Some of the files will also have an associated icon corresponding to the icon that file type will have in Windows Explorer When you run a solver process the result files from it will appear in the file list immediately after it is created and it will be continuously updated up until the process finishes Reduction This list shows the status and location of the results from the reduction process The icon in front of each link indicates whether the link has a recognized set of reduced matrices or not A green hatch
74. an image explaining the function definition and another with options for previewing the function in a graph Function Type o A W p Parameters o Parameter H 9 Linear z Slope 1 Slope 1 0 fto DOF Lr ZH vr ay Fedem Release 5 0 User s Guide 4 51 4 Mechanism Elements 4 10 Functions Function Type You can change the function type by selecting the new type from the pull down list The parameters and the help image shown in the panel are updated to reflect the new type Argument You can select any of the objects in your model that already is used as an argument by this or another function namely those having a sensor attached from the pull down list When an object has been selected specify which quantity you want to access on that object by selecting from the DOF and Var pull down lists Argument selection button By pressing this button you can select any object in your model to use as argument When the button is pressed the Guide Panel will prompt you to select an object Do so and press Done to accept the selection A sensor will then be created on the selected object which will appear in the Argument pull down list In addition to physical objects like Triads Joints etc you may also select Control output elements and other Functions as arguments o Parameters This frame contains the parameters of the selected function type Parameter Help This tab
75. and tire relaxations lengths were introduced in order to have a first order approach of the transient tire behavior This model was improved on the description for combined slip calculations in 1993 5 Bayle e o 6 proposed to have a more empirical approach reducing the complexity of the force calculations under combined slip conditions and yielding a considerably higher calculation speed Their method improved the calculation speed during the calculation of the Magic Formula parameters and during simulation calculations The latest version 7 combines the advantage of the previous versions and has been modified for the following aspects The self aligning torque has been made dependent on the side force by a new approach using the pneumatic trail in pure and combined slip conditions Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre The forces under combined slip conditions are calculated according to the proposal of Bayle 6 Formulae describing overturning moment have been introduced The transient tire behavior has been improved to enable zero speed Loading variations to tire lift off situations The parameters used in formulae are dimensionless improving manipulations with tire characteristics and parameter calculations fitting Scaling factors are introduced for vehicle tire optimization purposes A 5 3 Learning the Basic
76. and press the left mouse button on some empty space in the modeler until all the objects in question is deselected 3 Select three points of the perimeter defining a circle Confirm each point by pressing Done After setting the third point the defined circle will appear in the Modeler view 4 You may now select a point to place your objects along the circles axis or press Done once more to move the objects to the center of the circle Origin property Triads Links and point to point joints have a property tab called Origin Shown below This property tab is used to display and edit the position and orientation of the mechanism element in question The sensitivity of the fields will reflect whether the selected object is allowed to move considering its attachments etc without corrupting the model Summary Origin Re Position Oiertaior Reference Coordinate type Reference C Coordinate type Global 9 Me x Cartesian XYZ o Global EuleiZYX as X Y Z x z Rotx Deg Rot Deg RotZ Deg 0 37898701 o51 709998 1 25 90 0 0 0 0 0 Position This frame displays the data for the translational part of the position Orientation This frame displays the data for the rotational part of the position Fedem Release 5 0 User s Guide 3 13 3 Mechanism Modeling 3 5 Moving mechanism elements Reference CS The translation and rotation can both be displayed and edite
77. automatically imposed and based on the type of command in use For example sensors cannot be applied directly to links and Fedem will therefore limit your selection to other types of mechanism elements To make the selection even easier you can filter the selectable items by limiting the types of items displayed in the Modeler TIP To limit the display of mechanism elements click the General Appearance button on the Standard toolbar then disable Mechanism Symbols as necessary See also Section 2 7 4 General Appearance Selecting ground To select the ground during modeling simply click anywhere on the Reference Plane 2 6 2 Done When executing a command in Fedem the Guide panel prompts you to select items or locate points When you have achieved the desired selection press the Done button in the Guide panel TIP You can also press the center mouse button within one of the modeler windows or the Enter key on the keyboard to accept the selection 2 6 3 Cancel To abort or escape a command procedure press the Cancel button on the Guide Panel TIP You can also press the right mouse button within one of the modeler windows or the Esc key to cancel a command 2 18 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 7 Visualizing the model 1 2 Visualizing the model 2 7 1 3D Navigation The 3D navigation commands enables you to change the view without interrupting the current command or procedure There
78. axis Belt camber and yaw frequency gyroscopic effects IR n a Residual mass moment of inertia about Z axis tuned value for optimal perfor mance MA n a Value to be added to wheel rim multi ply with mO M B mp See Table B 3 on page B 5 Translation belt frequencies M R n a Residual mass tuned value for optimal performance C GRV Cory See Equation B 8 CONTACT_PATCH Q_A2 a See Equation B 33 Relaxation length amp enveloping behavior Q Al dat See Equation B 33 Relaxation length amp enveloping behavior Q_LBF dibf See Equation B 26 Enveloping behavior Q_LOS1 Glos1 See Equation B 27 Enveloping behav lor B Using the SWIFT Tyre Model B 4 Tire Model Parameters Table B 8 Definition of Parameters in Tire Property File Continued Ti teri oser I Notes a OCIO Tire characteristic if applicable Q LOS2 qdlos2 See Equation B 27 Enveloping behav ior Q_LIMP1 Glimp1 See Equation B 29 Enveloping behav ior Q LIMP2 Glimp2 See Equation B 30 Enveloping behav ior Q KC1 kel See Equation B 37 tuned value for optimal performance Tire damping for low speed Q_KC2 Oke2 See Equation B 37 tuned value for optimal performance Tire damping for low speed Q_AMIN amin See Equation B 35 tuned value for optimal performance Aligning moment for short wavelength around slip 0 FLT_A n a Contact length filter tuned value for
79. cam joint variables to model contact behavior it is often necessary to assign some associated damping to reduce fictitious oscillations due to sudden activation and deactivation of contact spring forces A constant damping coefficient is then sufficient as long as the follower is within the contact domain throughout the simulation However if the follower enters the contact domain once or several times during the simulation numerical instabilities may occur due to the sudden activation of the joint variable dampers because they are active only when the follower is within the contact domain To avoid this it might be necessary to scale the damping coefficient with a function see Section 4 7 2 Damper properties that varies gradually from zero as the follower enters the contact domain to one as the contact stiffness is activated Radial contact springs By enabling the Use radial stiffness toggle the springs associated with the x and y variables are referred to local polar coordinates in the xy plane instead Thus the x coordinate is then the radial distance from the cam curve to the follower and the y coordinate is the angle between the local Cartesian x axis and the axis extending from the contact point through the follower The contact domain will consequently be a circular cylinder instead of a rectangular one and the Thickness and Width parameters above will now define the radial and the angular in degrees extension of the contact
80. cece cece nen e A 33 A 7 3 Effect of Camber Angle ce cece cece eee cece nent ene ere A 34 A 7 4 Tire Model Output at Extreme Input Values c cece cence ees A 35 Standard Tire Interface STI cece e cece cere eect ences A 35 MF Datasets and MF Tool e cece cece ence eee n ence eens A 36 A 9 1 Tire MeaSUreMeENtS cece cece cece cece eee eet e teen E enn A 37 A 9 2 Calculation of Magic Formula Parameters sees eee eee nee A 37 Definitions sers Gere ota o a ico ed Sua ag e eh oto eb oe eod A 38 Referentes 15544 dcc e dU USER eae eas ea Mae A 40 Using the SWIFT Tyre Model IFREODHEUOR a Ceo cera Are od c le GR X Aca HR AER CR ao Ones a B 2 B 1 1 DYNAMICS 95 5 5d ek ARE Nae OEE aa sa wee ae eS eo SS B 2 B 1 2 Slip Force Calculation 0 0 cece cece cece cece emen B 2 B 1 3 R dd Np arenneren iy P cherie vhdbues la eh ewe dee I Y PNUPIx PI B 2 B 1 4 Refer ncesus xo v ARR M RAE MUR EPA UB EE B 3 N tatioN ER B 3 Force Evaluation e sr ce C Nar Suan Rees ava dis eq B 8 B 3 1 Rigid Ring Model 0 cece cece ence a ee eee hee B 8 B 3 2 In Plane Characteristics cece cece cece ence eee hee B 8 B 3 3 Out of Plane Characteristics 0 c cece cece cece eter eee nenne B 9 B 3 4 Vertical Force Characteristics 0 c cece e cece eee e ence cnet eneees B 10 B 3 5 The Effective Tire Rolling Radius cece eee ee eee eee e nee eeee B 14 B 3
81. circular fashion around the element where both clockwise and counterclockwise sequences are permitted The node numbers will possibly be reversed internally so that the element Z axis points in the user defined direction zPos defines the location of the rosette along the Z axis If the user wants the strains measured at the top of a plate the number at the Z pos column should be h 2 where h is the plate thickness A value of h 2 will give the strains at the bottom of the plate X_x X_y X_z These three numbers define a vector which is used to define the local X direction for the rosette coordinate system The vector is given in the link coordinate system The vector does not need to be given as a unit vector nor does the vector need to lie exactly in the element plane The X direction used for computations is obtained through a projection of the user defined vector onto the element plane Z_x Zy Z_z These three numbers represent a vector which is used for defining the positive Z direction of the rosette coordinate system The vector defined by the user does not need to be exactly perpendicular to the element plane As long as the vector has a component pointing out from the element plane the Fedem Release 5 0 User s Guide 6 39 6 Mechanism Analysis 6 9 Strain coat analysis Z direction for the rosette coordinate system will be correctly defined The rosette Y direction is implicitly defined through the X and Z directions
82. e2 en NAME name Parameter Value Type Description id Integer Group identifier ei Integer Element ID of the ith element in this group name String Name tag of this group Fedem Release 5 0 User s Guide C FE Link Interface C 2 Nastran Bulk Data File format C2 Nastran Bulk Data File format Fedem supports a wide range of Nastran bulk data entries see table below For most element types implicit conversion to a known Fedem element type is performed Refer to Nastran s Bulk Data File documentation for details about properties and syntax for each entry and the Fedem R5 0 Theory Guide Appendix A Finite Element Library for details about Fedem s library of elements FE models in Nastran bulk data file format can be directly imported as links into Fedem using the Import Link command see Section 4 1 1 Creating links by file import NOTE Each FE model to be imported into Fedem must be stored in a separate bulk data file with the Nastran Bulk Data File extension nas or bd Nastran Bulk Data Conversion BAROR BEAMOR CBAR CBEAM Same as CBAR CBUSH CELAS1 CELAS2 Same as CELAS1 CHEXA Supports both 8 and 20 nodes CONM1 CONM2 Same as CONM1 CONROD CORD1C CORD1R CORD1S CORD2C CORD2R CORD2S CPENTA Supports both 6 and 15 nodes CQUADA CQUAD8 Converted to CQUAD4 CROD Same as CONROD CTETRA Supports both 4 and 10 nodes CTRIA3 CTRIA6 Converted to CTRIA3 Comments
83. each link in question see Section 4 1 4 Link properties CAUTION The E N analysis will not include the effects from the residual stresses as it is based on strain values 1 When fatigue analysis is enabled the default is to use an integrated fatigue solver based on pre defined S N curves However it is also possible to use nCode instead if you have that software installed and the necessary licenses available To enable nCode usage enter the string useNCode in the Strain Coat Recovery Summary field of the Additional Solver Options dialog see Section 6 2 3 Additional solver options See Section 6 9 6 Using nCode FE Fatigue for more details on fatigue analysis with nCode 6 42 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 9 Strain coat analysis 6 9 4 Starting the analysis X Once you have set up the strain coat recovery summary options and gt performed the dynamics simulation you can start the strain coat recovery by clicking the Recover Strain Coat Summary button on the Solvers toolbar or Solve menu The Strain Coat Recovery is then performed on each link in the model which currently contains strain coat elements Links without strain coat elements are omitted automatically during the analysis 6 9 5 Strain coat recovery on element groups or individual links A strain coat recovery can also be performed on defined element groups or a selection of links See Section 6 2 4 Link and gro
84. eigval_ Calculated eigenvalues and associated eigen vectors from the dynamics simulation are stored in files named ev frs timehist_rcy_ Results from the stress recovery process will be stored linkwise in subdirectories The files will be named linkname _ frs gt eigval_rcy_ Results from the eigenvalue recovery process will be stored linkwise in subdirectories under this directory and will be named 1inkname 4 frs timehist_gage_ Results from strain rosette recovery are stored linkwise in subdirectories under this directory The result files will be named 1inkname f frs Fedem will also create ASCII and DAC files See Section 6 8 Strain rosette analysis summary_rcy_ Results from strain coat recovery are stored linkwise in subdirectories under this directory The result files are named linkname _ frs and if you create a rainflow matrix file it will be named linkname _fpp_ fpp where the running number is one higher than the corresponding frs file If you run FE Fatigue the result file will have a similar syntax as the fpp file and with the same running number Fedem Release 5 0 User s Guide 8 Managing Results 8 3 RDB directory structure ss dutycycle_rcy_ Results from Duty Cycle calculation is stored linkwise under this directory One result file will be created named linkname _ frs Strain Coat Recovery Summary file management When the Strain Coat Recovery p
85. exit false The curvePlotPrec option is effective for multi column ASCII and RPC files only The default value 0 half precision is applicable to RPC files only For ASCII files the default value is 1 single precision DAC files and single column ASCII files are always written in single precision This footnote also applies to the curvePlotPrec option of the Dynamics Solver E 20 Fedem Release 5 0 User s Guide F Beta feature documentation es AppendixF Beta feature documentation Some new features in Fedem are still in a state of Beta testing These features are typically available through commands or options entered in the description field of an entity s property window This means to enter the special character followed by a keyword and possibly some values into the description field along with the user description like in the example shown below See also Section 2 5 5 Property Editor Description InitTransVel 0 0 0 0 1 0 General Origin FE Node Additional Masses Additional Boundary Conditions Node No N A Mass 0 0 RS Rx Ix 0 0 Bu Ry y foo B Rz Reference Global Y iz o0 Due to the Beta nature of the features they should be used with some care The present way of accessing these features through the options or commands in the description field is subject to change or no longer being supported in future releases However most of the feat
86. file types input files D 2 intermediate files D 3 other files D 3 results files D 3 Finite Element FE dynamics in elastic mechanisms 1 2 material data 1 5 method 1 5 models 1 4 1 5 creating 1 5 generation of C 1 importing 1 4 nonlinear 1 4 storage 2 3 C 1 See also links nodes 1 4 first order transfer function block 5 7 five DOF joint 4 38 flip element direction 5 10 1m format 2 4 C 1 mm format 2 3 follower triads constraining 4 33 Force evaluation in SWIFT Tyre B 8 force vector 4 47 Fedem Release 5 0 User s Guide force vector orientation 4 47 graphic performance forces 4 46 increasing speed 2 22 2 26 format modeling tools 1 3 1m 2 4 graphics card settings 2 26 mm 2 3 graphs t1 2 3 about 7 3 free joint 4 29 abscissa label 7 4 free movement 3 10 adding legend 7 4 friction 4 22 4 28 4 29 4 31 4 35 controlling x and y axis range 7 7 behavior 4 38 creating 7 4 computing force 4 38 creating curves 7 4 creating 4 39 displaying 7 4 editing 4 39 displaying curve properties 7 7 parameters 4 39 dynamic updating 6 47 properties 4 39 dynamic viewing 7 17 with appropriate joint 4 39 enabling Autoscale option 7 4 fringe legend 7 35 exporting 2 35 customizing 7 35 naming 7 4 fringe value naming curves 7 8 selecting results 7 26 opening window 2 15 From and To options 4 47 ordinate label 7 4 front view 2 22 Possible Results list 7 10 7 14 ft1
87. files 4 20 print view 2 35 examples C 2 printing 7 21 identifiers C 2 result operation 7 9 t1 format 2 3 2 35 C 2 selecting results 7 10 Full Color 7 36 specifying properties 7 4 Full Color B W Limits 7 36 variables 7 10 Full Color Clipped Limits 7 37 viewing tips 7 18 function viewing values 7 3 creating 4 51 views 2 8 2 15 6 47 7 2 function keys 2 20 displaying legend 7 8 functions manipulating 7 17 properties 4 51 updating curves 6 47 X Axis Y Axis 7 8 G Gravitation 3 24 grid and snap 2 15 general appearance 2 24 manipulating 5 8 general transfer functions 5 7 ground geometric stiffness contribution link selecting 2 19 stiffening 6 21 6 23 6 24 group wise solving 6 9 geometrically nonlinear FE model Guide bar 2 17 treatment of 1 4 Fedem Release 5 0 User s Guide Index l 5 1 6 Index H hardware requirements 2 2 History of MF Tyre A 11 HyperMesh 1 4 hysteresis backlash block 5 6 deadband 5 6 ID and Topology panel 2 7 2 10 sensors 4 65 ID Number 2 11 I DEAS 1 4 identification numbers 2 9 importing links 2 8 initial equilibrium 6 24 analysis 4 19 6 24 Initial translational velocity 3 24 input and output blocks 5 3 input file types D 2 input force orientation 4 48 input signal amplifying 5 4 calculating and outputting power 5 4 integrator and limited derivator blocks 5 5 integrator block 5 5 Interactive Odometer 3 5 3 8 about 3 5 spe
88. in this chapter address the following topics Links Element groups Triads Joints Joint pair constraints Frictions Springs and Dampers Loads Tires and Roads Functions Sensors VY Y VYVYVYVN N Y Y YN Strain rosettes Fedem Release 5 0 User s Guide 4 1 4 Mechanism Elements 4 1 Links 4 1 Links As described in Chapter 1 Introduction to Fedem links are the basic components of Fedem models You can connect links with various types of joints to create a moveable mechanism Each link is either an FE Part represented by an FE model with nodes elements materials and physical property data or a Generic Part represented by a simplified model forming a semi rigid connection between other mechanism entities FE Parts The mass properties stiffness properties and dynamic properties of an FE Part are defined through its FE model defined by nodes elements materials and physical property data The FE model must be constructed in an external FE modeler such as one of those described in Section 1 5 Using FE models and then imported into Fedem You can use simple or complex links in your models depending on your needs and modeling capabilities Shown below is a simple FE link modeled with solid elements Link coordinate system The FE model representing the link is defined in the link coordinate system When the link is imported into Fedem this coordinate system is aligned with the global coordinate sy
89. is retained in memory and used as visualization unless a VRML model file is specified Fedem will not drop the FE data from memory until you actively enter or change the VRML model file name When switching back to FE Part Fedem will check that all the Triads are validly attached to the FE model See also Section 3 6 7 Invalid attachments Visualization only You can define the link to be used for visualization only The link will then be ignored by the solvers and actually serve as Fedem Release 5 0 User s Guide 4 7 4 Mechanism Elements 4 1 Links an extension of the Reference plane see Section 3 3 1 Reference Plane The link and all triads attached to it will thus be grounded NOTE You can toggle a link as Visualization only at any time during modeling but it is disallowed if the link has slave triads attached Finite Element Model FE Parts only This group of options concerns the FE model used Repository entry indicates the repository type and the name of the selected ftl file in Fedem s link database repository for details on the link repository refer to Section 4 1 5 Using link repositories If the model file has not yet been saved this entry will state the file name Fedem will use when you save your model Imported file indicates the name and location of the originally imported FE model file The unit conversion that was applied during the import is also displayed The Change button
90. is sampled Function The function to be plotted is chosen from this pull down menu The menu lists all functions currently in your Fedem model Auto increment Most functions have the option to have the resolution set automatically If used Fedem will determine which points are sufficient to describe the function and plot those In that case the specified increment is not used NOTE If plotting a Poly line function with Auto Increment set the domain Start x and Stop x is not used either In this case the domain is automatically adjusted to fit the curve data 7 2 6 Fourier analysis Options for performing a Fast Fourier Transform FFT of the curve data are found on the Fourier Analysis tab of the Property Editor panel The Fourier Analysis panel is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics Fourier transform oor r Time domain 2 Start 0 0 Stop 0 0 Entire o NoQHzcomponent M AY sample rate 10 01 Fourier transform On Off When toggled On the plotted curve is replaced by its discrete Fourier transform the Fourier transform is a representation of the curve in the frequency domain The value plotted is the magnitude of the transform Note that the scale and shift parameters specified for the curve see Section 7 2 7 Scale and Fedem Release 5 0 User s Guide 7 13 7 Postprocessing Results 7 2 Graphs Shift are applied to the curve da
91. is used by default The FE mass matrices are then represented by one diagonal matrix each where each diagonal term is the sum of the associated row or column of the corresponding consistent mass matrix The assembled mass matrix of the link will then also be diagonal except for some off diagonal terms created by the constraint equations if any Thus using lumped mass will reduce the memory requirements significantly compared to using a consistent mass matrix and will also speed up the reduction process as some of the matrix operations involved are simplified see equation 3 16 3 19 in the Fedem R5 0 Theory Guide NOTE To some degree using lumped mass does affect the results as it represents a simplification of the FE model The difference in the results may be significant for links with a coarse FE mesh However as the FE mesh is refined the difference becomes smaller Therefore it is recommended to use consistent mass on links not having a sufficiently fine FE mesh If you are in doubt try a test run using both consistent and lumped mass and compare the results The use of consistent mass matrix is toggled on off for the selected link through a button in the Property Editor panel see Reduction Options tab in Section 4 1 4 The default is off for new links imported into a model 6 3 4 Handling singularities during the model reduction In complex FE modelling it is inevitable not to have one or more defects in the FE model
92. l 7 l 8 Index rolling resistance formula A 33 slip formulas in A 18 steady state formulas A 18 switching from simple to complex models A 32 tire kinematics A 36 tire relaxation length A 30 tire rolling radius A 8 tire slip quantities A 11 tire road interaction A 3 transient behavior formulae A 30 units A 6 modal analysis 6 3 mode and time lists 6 34 mode shape analysis 6 4 setting up 6 33 specifying parameters 6 4 mode shape recovery 6 34 eigenmodes animations 7 28 options 6 34 mode shapes animating 6 33 6 34 expanding 6 4 model applying motion constraints 3 1 reduction process 1 4 storing contents 2 3 visualizing 2 19 model display color 2 27 complexity level 2 27 fog 2 26 transparency 2 27 model file creating new 2 5 directory 2 3 Model Manager selecting items 2 9 Model Manager Objects list 3 7 Model Manager panel 2 7 2 9 Model Manager Results list 7 2 Model Manager tabs 3 2 model objects editing properties 2 7 managing 2 7 2 9 model reduction 6 2 6 11 initiating manually 6 11 Modeler window 2 14 3 3 Global Directions 2 14 Interactive Odometer 3 8 locating specific points 3 5 manipulating the view 2 8 opening 3 3 Reference Plane 2 14 modeling aids stickers 3 6 commands 2 8 control systems 1 3 objects triads 4 18 programs 1 4 tools 1 3 3 4 Modeling tolerance 3 24 modeling tools 3 3 models 2 26 models and results constructing and v
93. level in long simulations However if you plan to use some of secondary variable results as input functions in subsequent simulations it can be essential to retain full precision in the saved results to obtain satisfactory accuracy in the latter simulations For this purpose the solver option double2 can be used double2 Save secondary variables in double precision When specified most of the secondary variables will be saved in double precision Some quantities that are not likely to serve as input in subsequent runs are always saved in single precision Thus the double2 option currently affects only the following types of quantities Fedem Release 5 0 User s Guide 6 27 6 Mechanism Analysis 6 5 Dynamics analysis 6 28 Triad velocities accelerations and forces Spring stiffnesses lengths deflections and forces Damper coefficients lengths velocities and forces Friction forces External force values and vector components Joint variables velocities and accelerations Tire contact point and wheel carrier forces VVVYVYVYY Control line variables Output selection While using default settings all primary and secondary variables available are output to file The selection of secondary variables to output however may be customized The al SecondaryVars option is used to switch on off the output of secondary variables altogether while a number of options of the form allNameOfEntityVars are used to control
94. locate points to place or move objects Performing commands makes use of three actions Select Done and Cancel Done YSE EAF Objects Results E fl Reference planes 2 16 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 6 Executing commands 2 6 1 Select To select items in your model or points on objects as references for moving or creating items place the cursor over the object or position and press the left mouse button left click The item is highlighted and its properties can then be edited in the Property Editor panel NOTE Some commands require that an object is selected from windows in the Workspace area only such as the Modeler or Control Editor Instructions regarding these commands are provided in the Guide panel TIP To deselect an item simply click an empty space within the Modeler window Snapping When selecting objects in your model the selection automatically snaps to a point on the object such as the nearest node on an FE link the center point of a joint and so on This makes your selection quick and accurate Snapping behaves differently on different types of objects FE parts VRML models CAD parts and mechanism symbols all have different snapping policies Selection snaps to FE nodes on FE parts to vertices on a VRML part to geometry features such as center points and edges on CAD parts and to important points on mechanism symbols Multiple selection
95. masters has been added As you add triads they will be oriented automatically to have sensible orientations related to the cam curve The z direction is set to point along the cam curve while the x direction considered to be up is calculated from the direction going from the master triad closest to the follower and to the follower triad To close the cam loop add the first master triad as the last one Fedem tries to set sensible directions on the master triads created but should any of the directions be inconvenient rotate them using one of the tools to move mechanism elements See Section 3 5 Moving mechanism elements 9 Define the spring characteristics you Z2 Preview of K a Spring stitt rans der A AEE need for the contact behavior and poaae 8000000 4 assign them to the correct joint variables Normally a non linear spring with a stiffness deflection curve as shown in the picture to the right will provide a decent contact behavior when assigned to the x translation DOF 6000000 4 4000000 2000000 4 0d T T T T T 0 001 0 0005 a 0 0005 0 001 Local coordinate system The local coordinate system for a cam joint has its origin on the cam curve at a point calculated as the closest point to the follower this point is referred to as the contact point The local x axis is then defined to be perpendicular to the cam surface and the z axis tangential to the cam curve The orientation of the l
96. mechanism for example when a triad is placed on an Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 3 Triads FE node and no other mechanism element is attached or when it is only used to attach a load torque axial spring or damper Coordinate system A triad is visualized as a coordinate system shown at right E when the triad stands alone and its coordinate system is referenced in one of the following ways E The triad s coordinate system is used by a sensor to X y measure a variable with components defined in the local triad coordinate system see Section 4 11 Sensors 9 The triad s coordinate system is used to define mass or inertia components for the triad see Section 4 3 3 Triad properties below The triad s coordinate system is used to define boundary conditions for use in the initial equilibrium analysis and or the system eigenvalue analysis see Section 4 3 3 Triad properties below Member of a Joint 4 The triads that are members of joints are visualized as integral parts of the different joint symbols Refer to Section 4 4 Joints for details 4 3 3 Triad properties To edit the properties of an existing triad select the triad in the Modeler window or Model Manager Objects list and make your changes in the Property Editor panel shown below General oi FE Node E 4 r Additional Masses Additional Boundary Conditions Node No N A Mass 0 0 X Re Ix 0 0
97. more accurate The rolling resistance torque has become a function of forward speed The influence of the camber on the peak F has been introduced Table A 1 lists the additional parameters Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 3 Tire Road Interaction ss Table A 1 New Parameters Introduced in MF Tyre 5 2 Name used in tire e Default Name property file Explanation Value Ayx LGAX Scale factor of camber for Fx 1 Ayy LGAY Scale factor of camber force stiffness 1 Aymx WMX Scale factor of Mx vertical shift 1 PDx3 PDX3 Variation of friction Mux with 0 camber l Ex1 REX1 Curvature factor of combined Fx 0 TEx REX2 Curvature factor of combined Fx 0 with load l Hy2 RHY2 Shift factor for combined Fy 0 reduction with load l Ey1 REY1 Curvature factor of combined Fy 0 lEy2 REY2 Curvature factor of combined Fy 0 with load Asy3 QSY3 Rolling resistance torque depending O on speed Asya QSY4 Rolling resistance torque depending 0 on speed 4 Furthermore LONGVL should be defined and have a positive value When the default values are used or omitted the tire model is fully backward compatible with MF Tyre version 5 1 A A 3 Tire Road Interaction The tire road contact forces are mainly dependent of the tire mechanical properties that is stiffness and damping the road condition that is the friction coefficient between tire and road the road struct
98. of contents for this ASCII file is given below All of the above mentioned files are created in separate directories for each link which then are placed in the sub directory timehist_gage_rcy_ in the result file hierarchy see Section 8 3 RDB directory structure ASCII output file format The rosette lt ID gt asc output file contains a heading and a data section See file cutout below The heading summarizes the strain rosette definition the data section lists all measurements made Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 8 Strain rosette analysis Strain rosette identifier 1 Link 1 Global nodes 844 846 830 828 Number of gages 2 Angle between gages 90 000 Position 2 336E 001 7 206E 001 4 500E 002 Position along Z axis 0 000E 000 X direction unit vector 0 000E 000 1 000E 000 0 000E 000 Y direction unit vector 1 000E 000 0 000E 000 0 000E 000 Z direction unit vector 0 000E 000 0 000E 000 1 000E 000 time eps_x eps_y gamma_xy eps_gagel eps_gage2 0 000000E 000 9 751E 018 3 048E 018 2 205E 018 9 751E 018 3 048E 018 2 000000E 003 1 835E 006 4 353E 007 2 367E 007 1 835E 006 4 353E 007 4 000000E 003 6 391E 006 1 490E 006 3 337E 007 6 391E 006 1 490E 006 6 000000E 003 1 041E 005 2 397E 006 1 660E 006 1 041E 005 2 397E 006 8 000000E 003 1 008E 005 2 320E 006 1 621E 006 1 008E 005 2 320E 006 Note that the cutout above is an edited version not showing the entir
99. of the worst DOFs will then be printed along with local DOF number object entity information and the actual solution increment in that DOF Finally you can specify the Dynamics Solver to abort the simulation after a certain number of such poor convergence warnings have been issued The DOF monitoring is controlled by means of Additional Solver Options see Section 6 2 3 Additional solver options The following options are available for this purpose default value in parentheses monitorWorst Number of DOFs to monitor on poor convergence 6 monitorlter Number of iterations to monitor before maxit 2 stopOnDivergence Number of warnings on possible divergence before the dynamics simulation is aborted 0 no limit 6 5 4 Starting the analysis Once you have set up the dynamics solver options you can start the gt dynamics simulation by clicking the Solve Dynamics button on the Solvers toolbar or in the Solve menu 6 5 5 Handling singularities during the dynamics analysis The Dynamics Solver has a similar treatment of singular equations during the solution of linear equation systems as the Link Reducer see Section 6 3 4 Handling singularities during the model reduction All singular DOFs will thus be attempted found in one go letting you fix them all before a new analysis is attempted However in the Dynamics Solver neither type of singularities true zero pivots or reduced to zero pivots are permitted The solver
100. of this joint variable as modeled and has the same interpretation as when the joint variable is Free see above Initial length angle Initial displacement rotation These radio buttons and fields work together to allow you to set the value that defines the initial configuration of the joint variable in the dynamics simulation Fedem Release 5 0 User s Guide 4 23 4 Mechanism Elements 4 4 Joints 4 24 You can choose to enter the initial length angle either as an absolute value or relative to the Length angle in model CAUTION If you define an Initial length angle that differs from the Length Angle in model this difference will be accounted for in the very first iteration of the dynamics simulation and thus lead to a dynamic shock effect However when the initial Static equilibrium analysis is switched on the force due to this difference is taken as a pure static load and the transient shock should be avoided Length Angle change You can prescribe the motion by a function The function controls the change of the variable relative to the nitial length angle If you rather would like to prescribe the absolute value of the variable set the nitial length angle to zero TIP You may plot the reaction force and input energy associated with a prescribed joint DOF by selecting the Force Moment value and Input Energy items under the joint variable node in question form the RDB selector see Selecting RDB results in Se
101. order to show the least values as red or worst To do this simply enter the Fedem Release 5 0 User s Guide 7 37 7 Postprocessing Results 7 4 Viewing animations worst value in the field labeled Max and the best value in the field labeled Min ignoring the relative size of the numbers When using a logarithmic mapping of the contour values make sure that both the max and min values are above zero If not Fedem will not be able to calculate valid contour colors log x where x lt 0 does not exist Tick marks There are two ways to control the tick marks on the color legend Either by setting the number of tick marks wanted or by setting the spacing between the tick marks When selecting Count Fedem will distribute the given number of tick marks evenly in the value domain When selecting Spacing Fedem will set tick marks with the given spacing between them starting at the first complete multiple of the spacing value When using a logarithmic mapping the supplied value is multiplied with the decade in question TIP When using logarithmic mapping choose Spacing as tick mark distribution and either 1 2 5 5 or 10 as spacing value Interpreting fatigue results When nCode calculates fatigue results some of the elements are rejected because they have near infinite life zero damage These elements are excluded form the max min calculations done by Fedem when reading the results Fedem assigns them a reference
102. position and orientation of its origin see Section 3 5 4 Origin property The joint variables are defined in this coordinate system See also Moving point to point joints in Section 4 4 3 Joint variable tabs These tabs display the properties related to the joint variable in question see Joint variable properties below Friction Some joint types allow you to add friction properties to the joint by selecting from the list of frictions in your model see Section 4 6 Frictions G Advanced tab This tab not shown above displays properties related to rotation formulation and spring inter connectivity of the joint see Advanced joint properties below Joint variable properties The joint variable tabs display the different options and settings for each joint variable The displayed options depend on the Constraint Type Fixed Summary Origin Tz Rz Constraint Type Rotation control PANT Angle in model 00 C Free g E 0 Prescribed C Spring Damper Length Angle in model This field shows the fixed value of this joint variable as modeled For rotational DOFs the value can be edited to Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints set a different fixed rotation state The 3D view will then update instantly showing the new rotation in the joint symbol TIP You may plot the reaction force associated with a fixed joint DOF by selecting the
103. produced by the Dynamics Solver can be exported in this manner If you need to include curves with results from other Fedem solvers in the same output file e g results from subsequent strain rosette analyses you have to run the Fedem Curve Export Utility module instead see Section 6 13 Automated curve export from multiple result database files Fedem Release 5 0 User s Guide 6 25 6 Mechanism Analysis 6 5 Dynamics analysis This toggle enables export of the rigid body motion of the computed response to a GLview VTF file This field shows path and name of the VTF file that will be written Press the Browse button to change file name or file format Q This label shows the selected VTF file format Available formats are Express Binary and ASCII You can enable disable the automatic start of a simultaneous rigid body animation when the Dynamics Solver is started This is useful when doing rapid prototyping simulations of short duration when it is essential to get quick feedback on the dynamic response CAUTION When the automatic VTF export is enabled the FE data for all links in the model is written to the specified VTF file before the Dynamics Solver is started For large models this may take some time especially if the FE data is unloaded and the Fedem Ul is blocked while the FE data is being exported 6 5 2 Result output control To control the size and contents of a dynamics analysis result database sev
104. program plink you will also need to define proper identification keys in your login directory such that you are able to login to the remote computer without being prompted for a password Please ask your system operator for assistance on such issues For further information on the ssh and PuTTY plink programs consult e g http www openssh com and http www chiark greenend org uk sgtatham putty 6 2 4 Link and group wise solving Fedem has the capability of running some of its solvers on individual parts of the mechanism links and element groups This is beneficial when dealing with big models where the solver execution may be both time and disc space consuming Note that these solver tasks act upon each part independently and do not affect the global response in any way The user is encouraged to identify critical parts of the model and recover just the results he wants on these parts Be aware that each time you recover results they are added to the result database regardless of their previous existence 6 8 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 2 Solver tools Link wise solving Solver processes that may be run on links individually are Reducer Stress recovery Strain Rosette recovery Strain Coat recovery and FE Fatigue A link wise solve process is started by right clicking on a link in the Model Managers Objects list choosing Solve and then the wanted process see illustration to the right
105. properties Figure A 17 Fit process Fx Fx Pure Pure Mx Mz Pure Pure Fxy Combined Y X Mz Mz Y Transient Combined Combine Transient The MF Tool software of Mf Tyre offers the engineer a user friendly tool to determine the MF Tyre parameters MF Datasets out of any Force and Moment tyre test data Next to software also MF Datasets can be selected out of existing Libraries See www delft tyre com Fedem Release 5 0 User s Guide A 37 A Using the MF Tyre Model A 38 A 10 Definitions A 10 Definitions General Table A 19 General definitions Term Definition Inertial coordinate system Inertial space according to ISO Road tangent plane Plane with the normal unit vector n tangent to the road in C Wheel centre O Centre of the wheel C axis system Coordinate system mounted on the wheel carrier at the Wheel center orientation according ISO Wheel plane The plane in the wheel centre that is formed by the wheel when considered a rigid disc with zero width Contact point C Contact point between tyre and road defined as the intersection of the wheel plane and the projec tion of the wheel axis onto the road plane W axis system Coordinate system at the tyre contact point C ori entation according ISO Tire Kinematics Table A 20 Tire Kinematics Definitions
106. properties 4 19 FE node 4 19 follower 4 33 in joints 3 16 4 18 master and slave 4 20 purposes 4 19 restraining movement 4 19 symbols 4 18 triangularization 6 12 U unattached elements Fedem Release 5 0 User s Guide color 3 21 See also general appearance undo option 3 7 Units 3 24 in MF Tyre A 6 user interface 2 1 V variables functions of 5 3 view achieving maximum zoom 2 20 axis rotation 2 21 bottom 2 21 flat colors 2 22 front 2 21 isometric 2 21 magnifying 2 21 manipulating 2 20 parallel 2 23 perspective 2 23 point rotation 2 21 rotate 2 21 rotating 2 8 selecting dynamic center 2 21 show top faces 2 22 side 2 21 Fedem Release 5 0 User s Guide solid shaded objects 2 22 top 2 21 View button 4 47 viewer options 2 26 viewing capabilities 2 14 views animations 7 2 graphs 6 47 7 2 W Workspace 2 7 2 13 Z Z displaying results 7 2 graph views 2 16 managing windows in 2 13 printing active graph view 2 35 offset 4 49 zoom F2 2 20 zoom all 2 23 Zoom and Pan toolbar View menu 2 23 7 17 zoom in 2 24 zoom out 2 24 zoom window 2 23 Index l 13 l 14 Index Fedem Release 5 0 User s Guide
107. recovery runs If multiple results are active for a given time set of time steps only those that were produced latest will be used NOTE If deleting a primary time history results file from a restart simulation e g the file th p 3 frsinthe view above all other simulation results are not automatically deleted as well as happens when the primary result file of the original simulation th_p_1 frs is deleted 1 The same is true when post processing results from recovery simulations that have been rerun several times on the same dynamics simulation results Fedem Release 5 0 User s Guide 8 7 8 Managing Results 8 3 RDB directory structure 8 3 8 8 RDB directory structure The map below outlines the RDB directory structure created by Fedem The hierarchy root is named modelname _RDB where modelname is the name of the current model For example the model file FrontSuspension fmm creates a results directory structure under the directory Front Suspension_RDB hub_ BSMGE fmx link_DB modelname _RDB hub ftl rod ftl rod_fl2 ftl link1 _ hub_SAM fsm hub ft fedem_reducer fco fedem_reducer fop rod_ BSMGE fmx link2 _ rod SAM fsm F rod ftl fedem reducer fco fedem reducer fop response ff timehist_prim_ th_p_ frs fedem_solver fsi fedem_solver fco fedem_solver fop timehist_sec_
108. resfile Name of result output file resStressFile Name of residual stress input file resStressSet Name of residual stress set samfile Name of SAM data file SR Save stress resultants to results database false statm Start time 0 stotm Stop time 1 strain Save strain tensors to results database false stress Save stress tensors to results database false terminal File unit number for terminal output 6 tinc Time increment 0 0 process all time 0 1 steps version Print out program version false vmStrain Save von Mises strain to results database false vmStress Save von Mises stress to results database false VTFavgelm Write averaged element results to VTF file true VTFdscale Deformation scaling factor for VTF output 1 VTFfile Name of VTF output file VTFinit Write initial state to VTF file false VTFoffset TF result block id offset 0 VTFparts Number of parts in VTF file 0 write nodes Save deformations as nodal data true write vector Save deformations as vector data false Fedem Release 5 0 User s Guide E 13 E Command line options Se E 5 E 5 Mode shape recovery options fedem_modes Mode shape recovery options fedem_modes Command line option Description Default value Bmatfile Name of B matrix file Bramsize In core size MB of displacement recov 1 ery matrix lt 0 Use the same as in the reducer 0 Store full m
109. same problem may be printed providing more information on the problem as it becomes available The messages on this higher level can be more user friendly due to more available Fedem Release 5 0 User s Guide 6 51 6 Mechanism Analysis 6 15 How to read error messages from the solvers information Some messages on the lowest level will have meaning for the program developers only It is however often necessary to have both the higher level and the lower level messages to get full insight into the problem So to understand the problem quickly it is therefore helpful to read these messages in reverse order starting with the last message the highest level and ending with the first one lowest level Sometimes you may ignore the lowest level messages those output to the res file only and still see what caused the problem 6 52 Fedem Release 5 0 User s Guide 7 Postprocessing Results p Chapterz Postprocessing Results This chapter introduces the options for postprocessing the results calculated by the various Fedem solvers You will learn how to set up graphs curves and animations Sections in this chapter address the following topics 9 Postprocessing environment Graphs Animations Viewing animations Fedem Release 5 0 User s Guide 7 1 7 Postprocessing Results 7 1 Postprocessing environment e 7 1 Postprocessing environment In Fedem postprocessing means evaluating the
110. see Creating curves from file and Creating curves from a function x Axis Y Axis to define the variables used for the x and y coordinates in a From RDB curve click the Edit button The Results Database Selector is displayed allowing you to pick the wanted results see Selecting RDB results below for details Alternatively one may also right click a curve in the Model Manager Results list and then select Edit X Axis or Edit Y Axis UT TIP While editing the x axis variable you can click Apply in the Results Database Selector then click the Edit button for the y axis and start selecting for the y axis Result Operation the pull down menus next to the Edit buttons list mathematical operations such as extracting the x component or 7 8 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs computing the length of a vector related to the result quantities selected for the x and y axis If the result quantity selected in Step 4 above is a Position matrix of either a Triad or Link the menu will also contain several angular quantities which can be derived from the position matrix See Derived angular quantities from position matrices below for further details on these items NOTE If you make a change to the Result Operation the curve changes dynamically in the graph view Export curve automatically toggles whether this curve shall be exported automatically by the solver to the f
111. simulation This happens because the stress free length of these springs then are undefined A warning is issued from the dynamics solver if this occurs Cam friction The friction parameters for cam joints are the same as those for prismatic joints with the exception of the equivalent force which is the sum of the x spring and x damper force in the cam joint The friction state depends on the slider variable only Fedem Release 5 0 User s Guide 4 35 4 Mechanism Elements 4 4 Joints 4 36 Cam thickness and width as contact domain The thickness and width parameters shown Thickness 0 1 in the Property Editor panel define a EE rectangular domain in the xy plane of the local coordinate system and is used to determine whether it is necessary to test if the follower is in contact or not The springs and dampers associated with joint variables are activated only when the follower is located within the distance Thickness 2 from the cam curve in the local x direction and within the distance Width 2 in the local y direction Use of a reasonable thickness is of great importance to ensure that the contact springs are attached to the correct cam segment a cam segment is the part of a cam curve between two triads One should avoid having the cam thickness so large that two cam segment have overlapping contact domains Use radial stiffness CAUTION When assigning highly non linear spring characteristics to the
112. slip conditions to tire model for transient combined slip situations The parameter USE_MODE of the MF Dataset determines the type of use of the tire model In the Table A 18 the possible options of USE_MODE are indicated Note that the maximum valid USE_MODE depends on the tire test data used to determine the MF Dataset parameters that is if only tire test data for pure cornering is fit ted the calculation of the contact forces under combined cornering and braking traction slip is not possible unless the user adds the required additional parameters Table A 18 The Different USE_MODE Values of MF Tyre EODE State Slip conditions ae ee pee t 0 spring 0 0 F 0 0 0 1 steady state pure longitudinal Fy 0 Fz 0 My 0 2 steady state pure lateral 0 Fy F M 0 M 3 steady state longitudinal and lateral F Fy F My My M not combined 4 steady state combined slip forces Fy Fy FZMy My Mz 11 transient pure longitudinal F 0 FZ 0 My 0 12 transient pure lateral O Fy FZ M 0 M Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 7 Some Practical Aspects p Table A 18 The Different USE MODE Values of MF Tyre USE eas MF Tyre output MODE State Slip conditions forces and torques 13 transient longitudinal and lateral F Fy F My My M not combined 14 transient combined slip forces Fy Fy F My My Mz A 7 Some Practica
113. solution type and the DMAP script Define OP2 files used to store the reduced mass m stiffness s and gravity g matrices from Nastran ASSIGN output2 2 name m op2 UNIT 71 ASSIGN output2 name s op2 UNIT 72 ASSIGN output2 name g op2 UNIT 73 lt name gt is some arbitrary string identifying this link NOTE The OP2 files are automatically converted to mxfiles when the Nastran bulk data file is imported into Fedem and the link is recognized as Reduced 6 16 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 4 Model reduction in Nastran Sess Specify modal analysis SOL 103 Include DMAP script INCLUDE nastran_dmap dat After the BEGIN BULK keyword the following commands must be added to perform the Nastran CMS reduction If you need to attach triads or joints to shell element nodes you need to turn on the drilling dof on the Nastran shell elements PARAM K6ROT lt value gt value 10 or a small value is recommended If it is set to O the drilling dof is omitted which is not what is desired The value is used to calculate an artificial stiffness that might influence the overall stiffness This might introduce undesirable effects and the resulting component modes should therefore be compared with component modes calculated without this artificial stiffness gt To get consistent instead of lumped mass representation the following bulk data command may be added PA
114. spring to the specified max and min forces When the spring force reaches any of these limits the spring stiffness vanishes and any further deflection of the spring is defined as the yield deflection Max Yield Force Spring force is always less than this value if this option is enabled Min Yield Force Spring force is always greater than this value if this is option is enabled Max Yield Deflection If the yield deflection exceeds this value either on tension or compression the spring is switched permanently off Fedem Release 5 0 User s Guide 4 45 4 Mechanism Elements 4 8 Loads es NOTE The Max Yield Force and Min Yield Force can also be defined through functions giving the spring variable yield limits This can be used to model clutch like behaviors in a spring coupling where you can smoothly or abruptly engage disengage the motion coupling To define a non linear spring with sudden failure and or yield limits you first have to define the non linear elastic force deflection or stiffness deflection curve through the Spring characteristics menu see Creating spring and damper characteristics above Then you create an Advanced Spring Characteristic via the same menu select the newly created Spring Characteristic in the Spring function pull down and then add the failure yield criterions The advanced spring characteristic is then available for selection in the Spring properties field of the Spring obje
115. than the required six zero rigid mode modes in the reduced system 6 for a link that can be caused by some over constraining in the FE model due to bad modeling etc By animating the six first mode shapes you can then see which rigid body modes are present and which are not and also see the mode shapes that replaced the missing rigid body modes All this might then give a hint towards the actual model error or weakness 6 3 7 Reduction of applied load vectors Along with the reduced mass and stiffness matrices the Fedem link reducer always computes reduced unit gravity load vectors of the link which are applied as a constant static load in the direction of the defined gravitation vector in the dynamics simulation In addition a set of load vectors corresponding to defined load cases in the FE data file are computed when such load definitions are present This includes both concentrated point loads and distributed surface loads on shell and solid elements These reduced load vectors may then be assigned time history scaling functions in the link property panel before the dynamics simulation is run see Reduced Loads tab in Section 4 1 4 Fedem Release 5 0 User s Guide 6 15 6 Mechanism Analysis 6 4 Model reduction in Nastran 6 4 Model reduction in Nastran As an alternative to the Fedem Model Reduction the model reduction may also be performed in Nastran Nastran supports a similar CMS reduction procedure as in Fedem
116. the Argument drop down menu in Functions and the Input menu in Control Inputs The symbol for a relative sensor is displayed in the Modeler window as shown to the right Managing sensors Sensors are managed in the Model Manager Object list If you have created ae pee sensors you can expand the Sensors aati 7 group to view the list of sensors in your Engine eng on rel sens model When a sensor is selected in the Objects lists it is highlighted in the Modeler window and its description is displayed in the Property Editor panel The ID and Topology Panel shown at right shows the triad s to which the sensor is attached and lists the functions or control inputs using it Relative sensor Ready Fedem Release 5 0 User s Guide 4 65 4 Mechanism Elements 4 12 Strain rosettes 4 12 3 4 66 Strain rosettes Strain rosettes are used to recover stresses and strains on a particular spot on your mechanism The output is similar to the output from real strain gages in addition to standard strain and stress quantities like Von Mises principal stresses strains and angle of max min principals They can be placed on any of the FE models in the mechanism both before and after solving the dynamics The strain rosette recovery is done by the strain rosette analysis see Section 6 8 Strain rosette analysis which recovers the strain rosettes data for one FE model at a time See also the Fedem R5 0 Theory
117. the numbers from the application where they are present e g a spreadsheet or a text editor On win32 based systems they have to be copied to the clip board by pressing Ctrl C The numbers are then inserted into the polyline function by clicking the list and pressing Ctrl V Refer to Section 4 10 4 Extrapolation to learn about the extrapolation of a Linear derivative function 4 62 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions Smooth trajectory 2 om Vmax t t sat cos 20 t lt 0 o2i lt 2 0 NE m 0 0 5 fv xj A 2 1 T V nax T z waf 7 1 e cosQa T 0 f T 5 lt t lt T 20 T Pial E t gt T A where t v vg and o f ae max fo A Vo Start abcissa value delay V V nax max f maximum velocity ido max f A max max f maximum acceleration L Lemax f 2 may T length of trajectory L ji L L 1 p Start Length Refer to other function This function type is reuses a previously Function Type defined function shape within this function Refer to other function i When this type is selected a new drop down None menu appears from which you can select the function you want to reuse the function shape definition from The definitions become linked and the changes you make to the referenced function will be reflected in the referring function directly 4 10 6 Time history input fi
118. the output of a range of entities E g allTriadVars requests the output of all variables related to triads while a ForceVars requests the output of all force variables in the simulation All available solver options are listed in Appendix E 3 Dynamics solver options fedem_solver File buffering and flush frequency As stated above the dynamics solver writes the results to up to three different results files Since the amount of data output per time step and the output frequency are different for the three files it is important to be able to synchronize the actual data output at given time steps This is needed especially when doing a simultaneous simulation and animation curve plotting For this purpose the flushinc option can be used flushinc Time between each database file flush 0 0 Do not flush results database let the OS decide 0 0 Flush at each time step no external buffers default gt 0 0 Flush at specified time interval use external buffers The default action flushinc 0 0 will do a physical flush of all open results files at the end of each time step Each open file is associated with an internal file buffer of fixed length For small models the amount of data per time step is usually less than the size of this buffer The data will Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis 6 5 3 therefore not be written physically to disk at the end of the tim
119. time steps option is T Use alltime steps enabled stress recovery Pee will be performed for all one computed time steps IV deformation JV stress resultant tensor between the specified I strain tensor IV stress tensor start and stop time The von Mises strain von Mises stress Reset button restores the max principal strain max principal stress default Time Interval min principal strain min principal stress values which are equal to max shear strain max shear stress the start and stop times z Automatic export to GLview VTF file of the simulation as i p Express File suess vif Browse specified in the Time tab J Contour range for Express YTF file von Mises stress only of the Dynamics Solver Min Jao Max Joo Setup dialog and 10 times the initial time oK A pply Cancel increment used in the GEI mew Een simulation You can choose which type of results to recover by activating the appropriate toggles For very large models it is recommended not to Fedem Release 5 0 User s Guide 6 31 6 Mechanism Analysis 6 6 Stress recovery analysis recover more results than you actually want to animate as the efficiency of the animation process and the size of the results database files is dependent on the amount of data computed NOTE If you choose to recover the stress and or strain tensors there is no need to also toggle on the derived quantities von Mises max principal etc
120. value that make them show up as little damage high life when using the ordinary Full Color legend mapping If Full Color B W limits are used those elements will show up as Black below legend domain if plotting damage or White above legend domain if plotting life If using Full Color Clipped Limits all these elements will be removed from the display leaving the interesting elements in the display The reference values Fedem uses are Damage 1e 20 Log Damage 20 All life plots repeats equnits Log 1e20 7 38 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 4 Viewing animations 7 4 4 Exporting animations The loaded animation can be exported to the mpeg 1 mpeg 2 and avi formats for viewing in an external viewer Avi export is available on Windows only The animation you have loaded forms the basis for the exported animation Through a simple setup dialog you will be able to control the speed of the animation To start export go to the File menu select Export and then Export Animation The animation setup dialog will appear O0 ccnmernpem ax the file name you want to export to File d stc vpmMain New_Animation mpeg Browse or click the Browse button o e All Frames to open a file dialog If you type the file name e manually the given extension C Omit Every Or zi will decide which format the C Export Only Every 5 2 animation will be expo
121. will and is located in SFEDEMDIR Templates default fmm If a different location for the template file is wanted the environment variable FEDEM TEMPLATE FILE can be defined to contain the desired path to the template file Predefined template files In the Templates directory in the Fedem installation you will find tree files de fault fmm default m fmmand default mm fmm The default fmmandthe default m fmmare identical and suitable for models using SI unit set while the default_mm fmm contains default settings that are suitable for models using millimeter newton and mega gram as unit set Simply copy the de ault mm fmmto default fmm if you prefer mm N Mg as your default unit set 2 4 3 Console window When Fedem is started on a windows system a separate console window can be opened in addition to the Fedem main window by specifying the command line option console This window lists some startup messages and may also contain some low level error messages during a Fedem session that normally can be ignored by users but sometimes might help understanding an abnormal incident WARNING Once opened the separate console window must remain open throughout the whole Fedem session closing it explicitly closes the entire Fedem session immediately without the option to save unsaved work Fedem Release 5 0 User s Guide 2 5 2 Learning the Basics 2 5 Touring the interface fs Um 2 5 TIP If abnormal behavior occur
122. x and y axes to accommodate new curves as they are added to the graph or when opening the graph view Disabling Autoscale allows you to fully control the x and y axis range Start time Stop time Use time interval You can enable the Use time interval toggle to specify a time interval for loading the graph Only the RDB data that fall within the specified time interval are loaded when the graph is opened or exported This only affects curves that are plotting simulation results Imported curves or curves plotting an internal function are not affected by these settings NOTE When you make changes to graphs or curves in the Property Editor the changes are updated dynamically in the graph view Curve properties Having completed the specification of a graph you want to set the properties of its associated curves To display the curve properties in the Property Editor panel select the curve in the Model Manager Results list The curve information is organized under six tabs Data Fourier Analysis Scale and Shift Appearance Curve Statistics and Fatigue The Data tab is Fedem Release 5 0 User s Guide 7 7 7 Postprocessing Results 7 2 Graphs Ss used to define the x and y values to be plotted and is described below The other five tabs are discussed in the subsequent sections Description Strain rosette 10 Gage 3 Stress vs Time 1 Legend Strain rosette 10 Gage 3 Stress vg Lime v Auto legend
123. 3 Previ Wipe esi whee prr DR DUE needed E VEA OPEN eee ea eS 4 52 A104 Extrapolation ens e esce Re ER ER He e Rer ER ECL EM ee 4 53 4 10 5 E nctlon TYPOS o erre yecter me tee ip RR ee te Ria ER REN ES 4 53 4 10 6 Time history input files 0 cece e cece nen ence ence 4 63 SENSON a aerian ie neata E nE ue bb deseo Abedss ua eS dU aie uat 4 64 AIRT Simple sensors oi oed eee Ru e E RUPES eee 4 65 4 11 2 Relative sensors cece cece cence e meme een 4 65 4 11 3 Mamaging Sensors ccc cece eee eene e emet 4 65 Strain FOSCUCS a atocveusbi sti bodes va bedctocaweueesedeneteanaay 4 66 Control System Modeling Control modeling environMent 0 cece cece eee eee ences 5 2 5 1 1 Control Editor et ise deine Re roto ET ee tex orabat met elut 5 2 5 1 2 Control toolbars ccc cece ccc eee een hehe emere 5 2 INPUt and OUTDUE soe rot eee REC OEC HN r RARE ERR 5 3 Control blocks eec o epe e a vti e GR 5 4 5 3 1 AMPIE S nereis mantaren x sive wre Pepper MUERE e Sa oN asteldly ooh 5 4 5 3 2 Binary input DIOCKS 0 cece cee cece eee eh 5 4 5 3 3 Integrator and limited derivator blocks 0 cee cece eee eee e ee 5 5 5 3 4 Time dependent bIOCKS 0 cece cece cen ence nene 5 5 5 3 5 Non continuous DIOCKS 0 cece cece cent meme 5 5 5 3 6 PI PD and PID controllers 0 ccc cece cece eee cece eee eeeeeeeeees 5 6 Fedem Release 5 0 User s Guide 5 4 5 5 Chapter 6 6
124. 3 14 01 E fedem modes co 0 3KB 5 15 2003 14 01 i PA fedem modes fon 11 KR 571672003 yur WARNING Deleting the primary time history results the file named th_p_1 frs will also cause all other results to be deleted WARNING When you delete results they are physically removed from disc and there is no way of getting them back at a later stage An exception to this is when you delete the primary time history result file In that particular case the results are not removed from disc until the next time you save your model 8 6 Fedem Release 5 0 User s Guide 8 Managing Results 8 2 Result File Browser 8 2 3 Result files from restart simulations When the Dynamics simulation has been restarted at least once see Time tab in Section 6 5 1 the Dynamics part of The File list in the Result File Browser will contain solver option and result files for each individual run The option files extension fop fco and fao and log files res from restart simulations will have a number appended to the base name indicating the actual restart number i e fedem solver 1 res whereas the binary result files xs will have numbers 3 or 4 and beyond depending on whether eigenmode analysis was activated Result File Browser Loader R43 fmm Les Sie Last modified opening RDB file timehist prim O001Vth p 3 frs Ep Reduction Header size 1649 Bytes lt bDyanic papa per M pyree B fedem_solver fco
125. 44 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 10 Duty cycle analysis BER 6 10 1 Getting started To run a duty cycle analysis you need several almost identical Fedem models The links you wish to run Duty Cycle simulation on must be present in all models and they need to have identical names and IDs in all events Other than that you are free to alter the models to your needs TIP A Duty Cycle setup is an ideal case to use a link repository One of the models must be a designated Duty Cycle model a model that is reserved for running Duty Cycle only This model cannot have any other results NOTE The chosen links need to be strain coated otherwise you will not be able to view the results In all the events you must run Strain Coat Recovery simulation on the chosen links In one model referred to as Master you will have to create a complete fpp file i e the fpp file must contain material data This is achieved by running FE Fatigue but you may omit running the actual computation answer No when asked if you wish to analyze job If you omit running the analysis it will be run for you in batch mode later NOTE Since FE Fatigue is run in a duty cycle analysis the nCode software needs to be installed for this process to work 6 10 2 Licensing needs To be able to run the Duty Cycle analysis you will need both a license from Fedem Technology and nCode 6 10 3 Setting up a Duty Cycle analysis In
126. 5 2 Learning the Basics 2 6 Executing commands 2 5 7 Output List The Output List window displays written output from Fedem such as a log of commands and solution and error messages This window allows you to observe the commands performed by Fedem To open the Output List window select Show Output List from the Windows menu or toolbar CT ains gt Reading C Program FilesifedemYuntitled fnm Result directory C Program Files fedem untitled RDB GLOBAL VIEW SETTINGS REF PLANE EIGENMODE Loading results from C Program Files fedem untitled RDB response 0001 gt Done readind The text in the Output List window is also written to a log file The name of this log file is the same as the current model file name but with extension og instead of fmm Therefore a new log file is opened whenever you Open a new model or perform a Save As command NOTE If a log file already exists for the model you open from an earlier Fedem session the output from the current session is appended to that file That means that the entire history of the Output List content for the model is recorded In addition the date and time of the model open and close operations as well as the Fedem version used are recorded to the log file 2 6 Executing commands When performing commands in Fedem the Guide Select Cancel panel prompts you with instructions for completing each command You may be asked to select mechanism objects or
127. 6 Effective Road Inputs 33 e eae RR LE es RIO a B 14 B 3 7 Contact Model 5 o rS ee alts Id ed eee be e ees s B 19 B 3 8 Switching from Simple to Complex Tire Model suussuue B 21 Tire Model Parameters 2 se eer rrr rh eee kt stan Re ry B 22 Fedem Release 5 0 User s Guide B 5 B 6 Appendix C C1 C2 Appendix D D 1 D 2 Appendix E E 1 E2 E3 E 4 E 5 Tire Property File Example 0 ese e cece cere ee eececece B 28 Road Property File Example ce ceeecec cence ee eeees B 34 FE Link Interface Fedem Technology Link format 0 cece cece eee e eee ence C 2 C 1 1 Synta vols extet te mu cave cRU EU Re SOS ORE UCM RON EIE C 2 C 1 2 NOGOS M E C 3 C 1 3 Structural elements 6 0 cece eee e een eee cence ence eee en eeenenee C 3 C 1 4 Mie E C 5 C 1 5 Ester EH C C 10 C 1 6 Strain Coat Elements 0 cece cece cece nen e tence enne C11 C 1 7 Strain Coat Properties sese ee alates oie rs neck RR ie ER E Rao C 11 C 1 8 Other identifiers 0 cece cece cece een e cece ehe C 12 Nastran Bulk Data File format 0 cece cece cece eee eens C 13 File Types and Usage linis cR RN RETE D 2 D 1 1 Inputfiles oce eto ruere e RLEee E Sr ane VEA P Een D 2 D 1 2 Intermediate files ciet ape rbv URA YEN eee barat own eee D 3 D 1 3 Results files cte seo ee URSI EN M D 3 D 1 4 Oth rfiles 5 oes ete n e eI MER RB E MS D 3 File usage for eac
128. 75e 006 B Concentric10 7 5e 006 10 Upper arm i 12 Lower am Eb ge Rigid joints i 1 KRG Base Frame 1 CEOLE S 6 25e 006 Links Se 006 1 KRE Wrist 2 FR 3 75e 006 j c4 1 PMAT 2 Se 006 4 K6 2 Rotating Base 1 Seran 006 4 amp Il Reference planes Ee aes 1 GROUND gt o SENA Rotational vel Integrator Rotation E Description k amp am Pat Origin Reduction Options Advanced KRG Link Am mesh 1 ow l l Upper am G FEPat Finite Element Model Rectan Generic Pat stor intemal D Models Other Robot_KS K6 Z 101 RDBWk DEKE Char anh A m Repository entry intemal D Models VOther Rabot 301 RDBWnk nge i Revolute joint 12 Lower am T Visualization only imported file D Models Other Robot_K6 k6_arm nas No unit conversion be Link 4 K amp 2 Roteting Base 1 Structural Damping Sealing of Dynamic Properties Mass proportional 08 T0 Stiffness proportional 0 01 Mas 12 Ready 1 2 Fedem Release 5 0 User s Guide 1 Introduction to Fedem 1 2 Non linear structural dynamics 1 2 Non linear structural dynamics In multibody applications such as suspension systems axle systems car bodies satellite appendages industrial manipulators medical equipment high speed mechatronic systems and so on some of the mechanism components ca
129. 92 QEZ3 0 QEZ4 0 17433 QEZ5 0 8957 QHZ1 0 0067668 QHZ2 0 0018847 QHZ3 0 14697 QHZ4 0 0042775 SSZ1 0 043285 SSZ2 0 0013747 SSZ3 0 73146 SSZ4 0 23758 QTZ1 0 05 MBELT 29 3 structural STRUCTURAL C_BX0 121 3872 C_RX 391 875 C_BTO 61 9617225 C_BY 40 049625 C RY 62 7 C BGAM 20 3349282 Fedem Release 5 0 User s Guide B 33 B Using the SWIFT Tyre Model B 6 Road Property File Example B 34 B 6 C_RP 55 8213716 K_BX 0 113761382 K_RX 0 45504553 K_BT 0 0398641872 K_BY 0 141974205 K_RY 0 45504553 K_BGAM 0 0185199476 K_RP 0 416698821 Q BVX 3 9567458 Q BVT 3 9567458 Road Property File Example In the road property file the road height is specified as a function of traveled distance In a road data file the left and right track data may be specified the appropriate track data is selected depending on the role of the tire in the model SWIFT uses a zero order sample and hold when evaluating the road profile as shown in Figure B 13 Changes in the height of the road profile are interpreted as steps For maximum accuracy it is important that the sample points coincide with the data provided by the user otherwise interpolated data will be used So you should use road data with a fixed sample interval and specify this value for ROAD INCREMENT in the MODEL section of the tire property file Typically the road sa
130. Adhesion Coefficient in Calculation Parameter m Parameter o 0 1 0 j 2 0 1 0 0 1 0 2 0 2 0 1 0 0 1 0 average slip angle o rad average slip angle o rad analytical adapted The band of modification is determined by Equation B 35 where asl is the slip value where full sliding is assumed Onin dominO sl B 35 In addition to the common relaxation length system the longitudinal relaxation length system is extended to Equation B 36 to increase damping at lower speeds The damping parameters are applied in the model through Equation B 37 In both equations the forward speed V4 is used instead of the rolling speed V_ to increase the robustness of the model kox kox o i c Vj Mex EXT x SX c V Sx B 36 ex cx k acres B 37 Cox 1 akez Val B 3 8 Switching from Simple to Complex Tire Model The SWIFT software incorporates a switch for tire complexity selection the parameter USE_MODE in the MODEL section of the tire property file Fedem Release 5 0 User s Guide B 21 B Using the SWIFT Tyre Model B 4 Tire Model Parameters B 22 B 4 Instead of full Rigid Ring tire dynamics the switch can be set for transient behavior only or steady state behavior Under these conditions the SWIFT model behaves just as MF Tyre The optional settings are given in Table B 7 Table B 7 Various Options for the Value of USE MODE Steady state Transien
131. B 9p25 Y2 MKy Nuy A 40 A 41 A 42 A 43 A 44 A 45 A 46 A 47 A 48 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula C dca 2 D F pi 2d q paf i a T dpz3lz dpz4Y i Ro F 9 i E t Gert d good dest 2 iate D aet c op lt 1 Sie 7 dgzi dpuzadf 4 H23 Veg EY B Qgzo X y Ayy q1Bz10 B C D u F 4 pz6 1 dpz df 3 i u d pg y dpzo9 df Yz i R Ruy An approximation for the aligning stiffness reads Table A 11 Aligning Coefficients Pure Slip A 49 A 50 A 51 A 52 A 53 A 54 A 55 Name Saban alle tire Explanation GBzi OBZ1 Trail slope factor for trail Bpt at Fznom GBz2 QBZ2 Variation of slope Bpt with load p73 QBZ3 Variation of slope Bpt with load squared GBz4 QBZ4 Variation of slope Bpt with camber GBz5 QBZ5 Variation of slope Bpt with absolute camber GBzo QBZ9 Slope factor Br of residual torque Mzr GBz10 QBZ10 Slope factor Br of residual torque Mzr qcz1 QCZ1 Shape factor Cpt for pneumatic trail qpz1 QDZ1 Peak trail Dpt Dpt Fz Fznom RO qpz2 QDZ2 Variation of peak Dpt with load Gpz3 QDZ3 Variation of peak Dpt with camber pz QDZ4 Variation of peak Dpt with camber squared Fedem Release 5 0 User s Guide A 23 A Using the MF Tyre Model A 24 A 6 Steady St
132. Dut of core Options a IV Equation solver out of core automatically set the size of the in core Cache size Automatic Manual J MB buffer as shown to the right It then I Ineeseo net wes reserves a fixed percentage of the free mcus W i UM se memory currently available the actual size is written to the res file This size may be overridden by switching to Manual and entering the desired cache size in the corresponding field You may also switch off the out of core feature completely by toggling off the Equation solver out of core option The Link Reducer will then abort if the problem does not fit in core There is also a similar set of memory usage options that affects the displacement recovery matrix and they work in a similar way Using the Manudl setting here corresponds to the Bramsize command line option NOTE You may switch back to the old in core equation solver used in previous Fedem versions by specifying the command line option sprSolver to the Link Reducer The out of core equation solver settings discussed above will then be ignored but the options for the recovery matrix still apply Fedem Release 5 0 User s Guide 6 7 6 Mechanism Analysis 6 2 Solver tools NENNEN Running solver processes on a remote computer If you are using a workstation connected to a file server in a local network together with other computers it may be advantageous to perform the simulation tasks on one of the other compu
133. E NEEESE TA 3 25 3 9 4 Gravitations eni 009 ok Sei ie ocd E Re wie Weasel LS 3 26 3 9 5 Initial translational velocity 00 0 0 cece cece eee eee e nee een ence 3 26 Mechanism Elements Elti Sach ond beat da in shat sue culate doge x hn ode D cept le ah ae eec 4 2 4 1 1 Creating links by file import cece cece cece I 4 3 4 1 2 Creating links from hard points 0 cc eee e cece ence eee 4 5 4 1 3 Copying links s eee a a e v dati nou ur Ur ape EE 4 6 Fedem Release 5 0 User s Guide 4 1 4 FINK properties i5 oe d RR E EDU PEE Es AAS Wee ri es 4 6 4 1 5 Using link repositories 0 eee cece cece tence eee e teen cece 4 14 4 2 Element GrOUDS desc oh eye can eor EE S Ee OR uc eos ars 4 16 4 2 1 Element group properties sss 4 17 43 ads Luck E pU REC sean spd dI I a E Reed ebd 4 18 4 3 1 Triads AM JOINTS sce op IR EDI VI A E E ENSE RN LER 4 18 4 3 2 Triad symbols eerte eut tent eee veu en E s d vedettes 4 18 4 3 3 Triad properties iii esses e Ree eee REX ESAE EERERERASE E 4 19 44 JOINTS ne e ERERIS IA edu EDEN E PESCA e essed 4 20 4 4 1 Joint Vatiabl6s rele RM IRLRRRRREE EDU ARREST RERO SEU LIE 4 20 4 4 2 Joint propertles cesseeceele a seas deed never ep tenons een 4 21 4 4 3 Point to point joints sae eaan E e E emnt 4 27 4 4 4 Poirit to path joints serr k died A rt LR RR E EE IER 4 30 45 Joint pair COnstralhlts cao oec Sutras scu piti Hp TH EET OTASIE SE 4 37 4 5 1 Geaf zi ue PRE Ver
134. Editor panel for the link see Reduction Options tab in Section 4 1 4 The default value is 1 0e 12 If the ratio between the current and previous value of a diagonal matrix element becomes less than the threshold value during the matrix triangularization the matrix is assumed to be singular The default threshold value is usually sufficient for well conditioned FE models However there might be situations where you have a natural high ratio between the stiffness or mass properties in different parts of a model In this case you may need to reduce the value to avoid a false error exit If you do get a singularity exit but is quite sure your model is sane although not that well conditioned you should check the actual Fedem Release 5 0 User s Guide 6 13 6 Mechanism Analysis 6 3 Model reduction diagonal decay value which is printed in the res file You may then try changing the Singularity criterion to a value less than this value and rerun the model reduction Note that the lowest admissible value is 1 0e 20 Any value lower than that will be ignored and 1 0e 20 will be used Negative pivots A model reduction may also reveal negative pivot elements in the stiffness or mass matrix This may happen if e g the link contains several poorly shaped elements especially shell elements However since the linear equation solver is able to handle negative definite matrices the reduction is not aborted when only negative pivots ar
135. Enable plotting of element results false plotNodes Enable plotting of nodal results false prepareBatch Prepare for batch execution This option can have the following arguments all all solvers reducer reduction of all links dynamics dynamics solver stress stress recovery for in links modes mode shape recovery in all links straingage strain gage recovery in all links straincoat strain coat recovery in all links purgeOnSave Purge inactive mechanism objects on false Save solve Start given solver s in batch mode This option can have the following arguments all all solvers reducer reduction of all links dynamics dynamics solver stress stress recovery for in links modes mode shape recovery in all links straingage strain gage recovery in all links straincoat strain coat recovery in all links dutycycle duty cycle in all specified links version Display program version and exit false Fedem Release 5 0 User s Guide E Command line options E 2 Link reducer options fedem_reducer E 2 Link reducer options fedem_reducer Command line option Description Default value autoMassScale Scale factor for auto added masses 1e 009 autoStiffMethod Method for automatic stiffness computa 3 tions in auto added springs 1 k Min diag K 0 1 lt tolFactorize gt 2 k Mean diag K lt autoS
136. Fedem provides the Control Editor modeling environment which combines the Fedem look and feel with graphical modeling tools similar to those of MATLAB Simulink These modeling tools are crucial when creating models of mechanical systems such as robots milling machines and space mechanisms See Section 2 5 Touring the interface and Chapter 5 Control System Modeling for more information about the Control Editor Fedem Release 5 0 User s Guide 1 3 1 Introduction to Fedem 1 4 What is a Fedem model As an alternative to the internal control system Fedem provides an interface for co simulation with MATLAB Simulink models see Section 5 5 External control systems 1 4 What is a Fedem model A Fedem model is a virtual test model designed by you to simulate your mechanical systems The virtual test model is an assembly of individual parts also called inks The mechanical properties of the links can be represented by either an FE model or a simplified stiffness description You connect links virtual joints springs and other elements to create an accurate virtual test model of a movable mechanical system or mechanism To minimize the time needed to calculate and simulate mechanisms Fedem s model reduction process reduces each FE model to a super element with external nodes These external nodes are defined at FE nodes that serve as connections between the various model entities in the assembly Once constructed a Fed
137. Figure A 5 Effective Rolling Radius and Longitudinal Slip R Ro Y Vx Y C Lo Fy A Vsx Re pA S P Fd Sc oue My For the estimation of the effective rolling radius Rg a Magic Formula approach is chosen The equation of the effective rolling radius R reads R Ro py Darctan Bp Fp A 4 in which Ro is the unloaded radius and the nominal tire deflection pr is defined by E PE C A 5 and the dimensionless radial tire deflection p can be calculated with d p A 6 Pry For a large range of tires appropriate coefficient values are 3 B 12 stretches the ordinate of the arctangent function a large value of B means a high slope at F 0 0 2 D 0 4 defines the shift from the asymptote at high wheel loads Fedem Release 5 0 User s Guide A 9 A Using the MF Tyre Model A 4 Axis Systems and Definitions pcm 0 03 F 0 25 defines the ratio between tire radial deformation r and effective tire deformation Low values are obtained for extremely stiff tires Figure A 6 The Tire Effective Rolling Radius as a Function of the Vertical Load B 8 4 D 0 27 and F 0 045 0 320 0 315 0 310 0 305 0 300 0 295 0 290 0 285 0 280 0 275 0 2000 4000 6000 8000 In Figure A 6 an example of the effective rolling radius is shown for a passenger car tire The approximation of Re is made with the proposed formula wit
138. File unit number for terminal output 6 tinc Time increment 0 0 process all time 0 steps version Print out program version false Fedem Release 5 0 User s Guide E 19 E Command line options E 8 Curve export options fedem_graphexp E8 Curve export options fedem graphexp Command line Description Default value option curvePlotFile Name of curve export output file response rsp curvePlotPrec Output precision for curve data files 0 0 half precision int 2 1 single precision real 4 2 double precision real 8 curvePlotType Format of curve export output file 3 0 ASCII separate file for each curve 1 DAC Windows separate file for each curve 2 DAC UNIX separate file for each curve 3 RPC Windows all curves in one file 4 RPC UNIX all curves in one file 5 ASCII all curves in one file cwd Change working directory fao Read additional options from this file fco Read calculation options from this file fop Read output options from this file frsFile List of results database files help Display this help and exit false licenseinfo Print out license information at startup false licensepath License file directory modelFile Name of model file with curve definitions rpcFile Get number of repeats averages and points per frame and group from this RPC file version Display program version and
139. For El such elements the use of file references may be beneficial The file reference replaces the file name in the element definition As the contents of the file reference the file it is referring to is changed so is the element input Thus if several mechanism elements receive their input from the same file reference and the contents of the file reference changes so does the input of a elements using it File references are created either by choosing File reference from the Mechanism menu or by right clicking an empty space in the Model Managers Objects list choosing Create and then File reference Then select one or more files in the File Open dialog that appears One file reference will be created for each selected File references are set as input in mechanism elements by choosing the wanted reference from the pull down menu of the input file field TIP If all tires in a model are created from the same file reference their tire definitions may all be switched simultaneously TIP If the several polyline from file functions use the same RPC file reference the input for all functions may be changed quickly Fedem Release 5 0 User s Guide 3 23 3 Mechanism Modeling 3 9 Model preferences 3 9 3 24 Model preferences In the Model Preference dialog you can adjust several parameters regarding the model Model description This field lets you add notes to your model file Units The consistent unit se
140. Guide Section 9 5 Virtual strain gauges for the theoretical basis of strain rosettes Strain rosettes are defined by selecting 3 or 4 FE nodes and the direction of the first leg of the rosette The nodes defines a strain element in which the strains and stresses is calculated at the centroid of the element based on the deformation of the nodes Material properties and shell thickness are extracted from the underlying FE mesh but can be overridden manually As the picture to the left indicates the strain rosette symbol consists of different parts and visualizes several aspects of the virtual strain rosette Q n enlarged symbol of the strain rosette to make it easier to find 2 Lines connecting the FE nodes used showing a wireframe of the strain element Enlarged arrows showing the directions of the particular legs within the strain rosette Leg 1 2 and 3 is distinguished by the number of lines used to draw the head of the arrows A small symbol showing the exact position of the virtual strain rosette The position shown also includes the shell thickness or layer position an will thus often be above the strain element wireframe Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 12 Strain rosettes EE The different features of the strain rosettes is accessed through the strain rosette property panel shown below Orosete type Single qage v Set start strains to zero 5 Qus 416 387 515 494 Edit
141. I text file Time history data ASCII txt xy paired coordinates rsp MTS RPC file Time history data Binary drv tim tpf TNOTire file Tire model description ASCII tir COSIN Tire file Tire model description ASCII rdf Road property file Road description ASCII D 2 Fedem Release 5 0 User s Guide D File Types and Usage D 1 2 Intermediate files Fedem uses the following intermediate files to store analysis options and simulation data from the analyses Ext File type Format fsi Fedem Solver Input file ASCII fCO Fedem Calculation Options file ASCII fOD Fedem Output Options filet ASCII fao Fedem Additional Options file ASCII fsm Fedem SAM data file Binary fmx Fedem Matrix file Binary Changes to files of this type affect the calculated results t Changes to files of this type do not affect the calculated results D 1 3 Results files The following table lists the results file types Ext Filetype Format frs Fedem results database file Binary res Fedem results output file ASCII fpp nCode rainflow matrix file Binary fef nCode nodal elemental dam ASCII age results D 1 4 Other files The following table lists all other file types used by Fedem Ext Filetype Format fcd Fedem unit conversion file ASCII fsn Fedem S N curves file ASCII Fedem Release 5 0 User s Guide D File Types and U
142. L VERTICAL STIFFNESS 196261 VERTICAL DAMPING 50 BREFF 9 DREFF 20 23 FREFF 0 01 FNOMIN 4000 Q REO 0 997448166 Q V1 7 15073791e 005 O V2 2 4892 Ox 14 3468 OF 0 i 0 BOTTOM_OFFST 2 01 BOTTOM TRNSF 1900 BOTTOM STIFF 2E 6 long_slip_range LONG_SLIP_RANGE KPUMIN wd KPUMAX 135 slip_angle_range SLIP ANGLE RANGE ALPMIN 1 5708 ALPMAX 1 5708 inclination_slip_range INCLINATION ANGLE RANGE CAMMIN 0 2619 CAMMAX 0 2619 vertical_force_range VERTICAL FORCE RANGE FZMIN 0 FZMAX 9000 scaling SCALING COEFFICIENTS LFZO E LCX m LMUX E LEX 2 B 30 B Using the SWIFT Tyre Model B 5 Tire Property File Example LKX LHX LVX LGAX LCY LMUY 1 LEY 1 LKY LHY LVY LGAY LTR LRES LGAZ LXAL LYKA 1 LVYKA 1 LS 1 LSGKP 1 LSGAL 1 LGYR 1 eer np PORRPOORR TRIS H SSS SSSS fees SS SS Sas ARAA longitudinal LONGITUDINAL COEFFICIENTS PCX1 1 6846 PDX1 152096 PDX2 0 03705 PDX3 0 PEX1 0 34446 PEX2 0 095439 PEX3 0 020488 PEX4 0 PKX1 21 512 PKX2 0 16314 PKX3 0 24502 PHX1 0 0016331 PHX2 0 001517 PVX1 0 PVX2 0 RBX1 12 35 RBX2 10 767 RCX1 1 0918 REX1 0
143. Mechanism modeling tools Creating mechanism elements Moving mechanism elements Attaching and detaching elements Deleting mechanism elements Using file references in mechanism elements VVVVVYVVYY Model preferences Fedem Release 5 0 User s Guide 3 1 3 Mechanism Modeling 3 1 Basic assembling techniques 3 1 Basic assembling techniques There are three main approaches to assemble a Fedem model A From a SolidWorks FedemSolid or NEiFusion CAD assembly If you have a CAD assembly of your model and have one of the mentioned CAD systems available you can directly transfer the complete assembly to Fedem Then all the links will be in place so what is left is to connect the parts by adding joints etc With FE models or VRML geometry If you have VRML geometry or FE models of your parts assembling a Fedem model means to import the links fit the parts together by moving and or rotating the links as necessary and then connecting them by creating and attaching joints With hardpoint positions When you only have hardpoint information it is more convenient to place the joints in space at the hard points and then connect the joints by creating generic parts from the triads in each joint Other mechanism elements such as springs dampers loads and so on can be added in the same manner either by placing triads on an FE model or placing them in space and attach them to FE model less links When assembling a model in F
144. Modelling Proceedings of the 2nd International Collo quiums Tyre Models for Vehicle Dynamics Analysis Vehicle System Dynamics Volume 27 Swets amp Zeitlinger Amsterdam Lisse 1996 Fedem Release 5 0 User s Guide A 41 A Using the MF Tyre Model A 11 References A 42 Fedem Release 5 0 User s Guide B Using the SWIFT Tyre Model AppendixB Using the SWIFT Tyre Model Delf yre This chapter contains proprietary information of TNO The contents of this chapter may not be disclosed to other parties copied nor duplicated for commercial use without the prior written permission of TNO The SWIFT Tyre model combines a Magic Formula slip force description with a rigid ring model and has been validated by experiments up to frequencies of 60 100 Hz Typical applications of the SWIFT Tyre model are durability studies shimmy analysis chassis control system evaluation that is ABS ESP and cornering on uneven roads This chapter includes the following sections Introduction Notation Force Evaluation Tire Model Parameters Tire Property File Example VVVYVY Road Property File Example Fedem Release 5 0 User s Guide B 1 B Using the SWIFT Tyre Model B 1 Introduction B 2 B 1 B 1 1 B 1 2 B 1 3 Introduction The Magic Formula is a widely used and accepted method for modelling tire forces and moments under steady state rolling conditions At higher excitation frequencies gt 1 2 Hz relaxation e
145. N Switching to single precision storage of the B matrix should normally have no influence on the dynamics simulation results However if the link s FE model is poorly conditioned e g there is a large span in the stiffness properties over the link there might be minor loss of accuracy in the recovery results due to the truncation of the B matrix elements stored on file NOTE For links that are reduced with component modes see bullet 2 above the single double precision storage option also applies to the file containing the component mode shapes the E matrix file Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links Reduced Loads tab On this tab you can assign time histories for load cases that are defined in the FE link data file The associated reduced consistent load vectors are computed by the link reducer and stored in the link repository together with the reduced stiffness and mass matrices Part Origin Reduction Options Reduced Loads Advanced LoadCase Delay Load woos ae LAIBZ Eej e m o Function E o Load Case This column contains the user defined load case ID for each load set defined in the FE link data file Delay If the load amplitude is defined by a Function this value is used as a shift to the function argument i e if the amplitude is specified as a function of time f t then the actual amplitude becomes f t Delay This is useful when each load case define the l
146. OFs of the cam joint Such rotational stiffness damping might be beneficial as a stabilization tool in some cases WARNING The rotational DOFs in a Cam joint are not suited for representing large rotations However this affects the solution only when some of these DOFs are Spring Damper constrained Therefore when Spring Damper constraining the rotational DOFs you must ensure that the added stiffness is high enough to keep the rotations small typically Rx 0 3 Ry 0 6 and Rz 3 0 radians If not the solution will probably diverge The initial values of the cam joint variables are interpreted differently compared with the other joint types The Length Angle in model quantity is always zero for all variables regardless of the modelling position of the follower For the Tx and Ty DOFs this means that the deflection is always calculated as the distance from the contact point to the follower in the local x and y directions respectively However for the Tz Rx Ry and Rz DOFs the deflection is measured relative to the modelling position of the follower The stress free length angle of any springs associated with these DOFs are then also defined relative to these initial positions WARNING If the follower is not within the contact domain of the cam joint see Cam thickness and width as contact domain below at the beginning of the first time step the rotational springs as well as the slider spring if any are ignored throughout the
147. OTE The expanded mode shapes for one link are stored in a single frs file provided all modes are expanded for the same set of time steps However if only one mode is expanded for a different set of time steps than the other modes one frs file is created for each expanded mode Therefore if you are expanding a large amount of modes it is advised to select the same time steps for all modes in order to limit the number of files in the results database as this might impact the post processing performance 6 7 20 Starting the analysis Once you have set up the mode shape recovery options and performed ED T the dynamics simulation you can post process the modes at the selected times by clicking the Recover Mode Shapes button on the Solvers toolbar or Solve menu When Fedem has postprocessed all the selected modes you can animate the mode shapes see Section 7 3 Animations for more information 6 34 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 8 Strain rosette analysis p n 6 8 Strain rosette analysis The strain rosette analysis recovers the stresses and strains on the virtual strain rosettes defined in your model See section Section 4 11 3 Strain rosettes on how to create and edit virtual strain rosettes The output is similar to the output from real strain gages in addition to standard strain and stress quantities like Von Mises principal stresses strains and angle of max min principals 6 8 1 Strain rose
148. PEx1 PEX1 Longitudinal curvature Efx at Fznom PEx2 PEX2 Variation of curvature Efx with load PEx3 PEX3 Variation of curvature Efx with load squared PEx4 PEX4 Factor in curvature Efx while driving Pkx1 PKX1 Longitudinal slip stiffness Kfx Fz at Fznom Pk PKX2 Variation of slip stiffness Kfx Fz with load A PKx3 PKX3 Exponent in slip stiffness Kfx Fz with load A Pra PHX1 Horizontal shift Shx at Fznom PHx2 PHX2 Variation of shift Shx with load Pvx1 PVX1 Vertical shift Svx Fz at Fznom Fedem Release 5 0 User s Guide A 19 A Using the MF Tyre Model A 6 Steady State Magic Formula E Formula Lateral Slip Pure Slip Figure A 10 Lateral Slip Condition Excluding Aligning Torque Pure Cornering L L 2 F Fp y F A 28 Fo D sin C arctan B a E Ba arctan B a Sy A 29 ay OL Spy A 30 the scaled camber angle Yo Y ees A 31 with coefficients C Poyi hey A 32 D uF A 33 Hy pyi Popda 0 Ppysty ay A 34 E yi Pgydf 07 Ways Pean la MC lt 1 A 35 K PxyiF2o8in Zarctan F pF 0AF 3 ad Pry3lVy p gy B C D EN at a 0 A 36 B K C D A 37 Spy Pry Piyf May Paty A 38 Sy Fz yi t Pry Ayy yy3 Prya dE 3 3 Apy A 39 A 20 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula se Table A 10 Lateral Coefficients Pure Slip
149. R 3 or ISR 4 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 3 Storing models and results nSoft 2004 FE Fatigue 6 Simulink integration for external control system MATLAB 6 1 Simulink 4 or Matlab 6 5 Simulink 5 gt FTire Tire road integration FTire v2 7 1 October 2008 and later 2 3 Storing models and results Fedem uses the following files and directories to store the contents of a Fedem model The mechanism assembly description and all simulation parameters are saved in the Fedem Mechanism Model mm format This file is called the model file and contains the complete description of your model except the link files and the simulation results The link files and all the simulation results are saved in a directory named modelfilename RDB the model name specified by the user is substituted for modelfilename Fedem creates this directory in the same location as your model file Within this directory the link files are stored in a directory named 1ink DB unless a link repository is used see Section 4 1 5 Using link repositories Appendix D File Types and Usage contains more information about Fedem file types whereas the directory structure is shown in Section 8 3 RDB directory structure 2 3 1 FTL format The Fedem Technology Link t1 format is used to store FE models as sets of data in text format see Section C 1 Fedem Technology Link format for more info
150. RAM COUPMASS 1 If coupled mass is not used the DMAP script can be simplified since Mie Mei 0 Definition of static modes external dofs Use ASET or ASET1 entries to define the external dofs To get 6 DOF Triads all nodes in the ASET active dof set must have 6 active DOFs A typical bulk entry is ASET node id1 123456 node id2 123456 Adding component modes generalized dofs If component modes generalized dofs are desired the following bulk entries must be specified EIGRL 1 lt idn gt SPOINT lt id1l gt lt id2 gt lt idn gt QSET1 0 lt id1l gt lt id2 gt lt idn gt Here lt idn gt is the number of component modes Fedem Release 5 0 User s Guide 6 17 6 Mechanism Analysis 6 5 Dynamics analysis 6 5 E 6 5 1 Dynamics analysis To control the dynamics analysis parameters click the Dynamics Solver Setup button on the Solvers toolbar or Solve menu The Dynamics Solver Setup panel will appear and allow you to adjust the process setup In depth information about the time integration process may be found in the Fedem R5 0 Theory Guide Section 7 3 Newmark integration algorithm Dynamics Solver Setup The control parameters for the Dynamics Solver are placed on six tabs labeled Time Integration Tolerances Eigenmode Initial Equilibrium and Output Time tab The time domain of the dynamics simulation is controlled through the following parameters You can
151. RNSF Defines the size of the transition range where the normal spring curve is smoothly changed into the bottoming spring curve see Figure B 7 The unit of this parameter is force B 3 5 The Effective Tire Rolling Radius The effective tire rolling radius Re is estimated using a Magic Formula approach Equation B 23 holds the formula for the effective tire rolling radius R Ro pp g Darctan B p Fp B 23 The nominal tire deflection rFzO is defined by Equation B 24 C radial tire stiffness and the dimensionless radial deflection is calculated using Equation B 25 F z0 Pro B 24 Fz0 C p c B 25 P Fzo B 3 6 Effective Road Input The standard single point contact model is valid for vertical road input for wavelengths larger then the contact length gt 0 2m For short wavelength obstacles the enveloping behavior of the tire needs to be described more accurately The enveloping properties of the tire are described in SWIFT by so called basic functions This method is B Using the SWIFT Tyre Model B 3 Force Evaluation incorporated for steps in road height and stochastic road input is treated as a sequence of steps The phenomena that occur when a tire is rolling on an uneven road are illustrated in Figure B 8 i O B 8 Tire Enveloping Behavior lengthening of response b swallowing c filtering of oneveness filterec respor 7 at axle actual road surfac The basic function c
152. Reference Plane To open E the Item Appearance window click the tem Appearance button on the u Standard toolbar and select a link or the Reference Plane The Item Appearance window is displayed as shown below TIP To change the appearance of a hidden link select the link in the Model Manager Objects list after clicking the Item Appearance button Dy everr etal _conticls tie o level of com plexity Qeeveiar Derai displayed in the model o Color controls the RGB Polygons Reduced Surface settings of the selected link lines Suae or Reference Plane e Material controls the Qo shininess and transparency Red I zz of the selected link or Reference Plane green a In the Level of Detail area the Bis d umm E Polygons and Lines settings Qa allow you to change the complexity of models displayed Shininess Hr in the Modeler Changing these a eee settings can improve the graphic performance of 3D rendering Polygons can be displayed at five levels of detail Surface and Internals Reduced Surface and Internals Surface Reduced Surface and Off The default level is Surface 2 26 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 7 Visualizing the model 1 Surface and Internals With polygon detail set to Surface and Internals element faces from solid elements inside the links are shown together with the surface faces of
153. Release 5 0 User s Guide F 3 F Beta feature documentation F 1 Joints F 1 6 F 1 7 F 4 The default master slave joint formulation is then not used which for the Free Joint only is a transformation of the free DOFs from the slave Triad to the joint variables and no constraining With the alternative formulation the added spring and damper properties are applied directly in the global coordinate directions between the two triads instead and no change in free variables There are no eccentricity contributions either when the force between the two triads is not attacking along their common axis Consequently this free joint is somewhat equivalent to a BUSH element on the system level see the Fedem R5 0 Theory Guide Section E 10 BUSH Prismatic Joint and Cylindric Joint Both Prismatic and Cylindric Joint can take the command Extended in the description field Entering this command allows the follower to travel beyond the first and last triad of the track When the follower is past the beginning of the track the first two triads receive the contact force in a statically consistent manner When the follower is past the last triad the last two triads receive the contact force The default rotational parameterization of the Cylindric Joint is Euler Z Y X rotations but this can be changed to components of the rotation axis vector by entering the command RotAxisParam in the description field of the selected Cylindric
154. S Prinsens gate 32 N 7011 Trondheim Norway Phone 47 72 90 03 00 Fax 47 72 90 03 01 Web http www fedem com Technical Support support fedem com Sales Pricing and General Information sales fedem com Fedem Release 5 0 User s Guide Fedem Release 5 0 User s Guide Chapter 1 1 1 12 1 3 1 4 1 5 1 6 1 7 Chapter 2 2 1 2 2 2 3 2 4 Fedem Release 5 0 User s Guide Table of Contents Introduction to Fedem Whats ROM occa corer cuetava rs te x Gh exce Do REIN ass Mestad 1 2 Non linear structural dynamics cece eee e cece cece een eeees 1 3 Control systems in mechanical analysis e cee e eee eeee 1 3 What is a Fedem model sss 1 4 Using EE riodelso eI MR IR EETULH EE UOI a eee es 1 4 CAD Initegratlon co ecc eet Deu Ee uer 1 5 Fedem solver MOdules ccc cece cece tence tence eee eneeees 1 5 1 7 1 Red cer EON II BR EDU ERR 1 6 1 7 2 Dynamics Solvet 2isie ruere ute pe ch Rape E RRIPUB ERR METER pas 1 6 1 7 3 Stress Recovery eee cee tee eee teen nee hh rh n 1 6 1 7 4 Mode Shape Recovery ccc e cece eee eect ener mme hee 1 6 1 7 5 Strain Rosette Analysis 0 cece cee cece cece eee n cnet en enenenenee 1 6 1 7 6 Strain Coat Analysis 00sec ccc e cece erence heme 1 7 1 7 7 Curve Export Utility eese rr Rhe reete e Rte cates edd 1 7 Learning the Basics System requiremehits sdnoeu o rx ced de d eee n recte i hr one ros 2 2
155. SECTION gid PORIENT oid PBEAMECCENT eid PBEAMPIN bpid PEFFLENGTH lid PNSM nid VDETAIL vid FFT3 id n1 n2 n3 PMAT pid PTHICK gid PNSM nid VDETAIL vid FFQ4 id n1 n2 n3 n4 PMAT pid PTHICK gid e tPNSM nid VDETAIL vid TET4 id n1 n2 n3 n4 PMAT pid VDETAIL vid TETIO id n1 n2 n10 PMAT pid VDETAIL vid WEDG6 id n1 n2 n6 PMAT pid VDETAIL vid WEDG15 id n1 n2 n15 PMAT pid VDETAIL vid HEX8 id n1 n2 n8 PMAT pid VDETAIL vid HEX20 id n1 n2 n20 PMAT pid VDETAIL vid Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format E Element statements BUSH id n1 n2 PBUSHCOEFF bcid PBUSHECCENT beid tPORIENT oid PCOORDSYS csid VDETAIL vid SPRING id n1 n2 PSPRING sid VDETAIL vid RSPRING id n1 n2 PSPRING sid VDETAIL vid CMASS id n1 PMASS mid VDETAIL vid RBAR id n1 n2 PRBAR rid VDETAIL vid RGD id n1 n2 nn PRGD rid VDETAIL vid WAVGM id n1 n2 nn PWAVGM wid VDETAIL vid NOTE The identifiers correspond to the element types defined in the Fedem R5 0 Theory Guide Appendix A Finite Element library NOTE The square brackets denote optional parameters The vertical bar means that either one of the two parameters on each side of it may be specified but not both NOTE The elements BUSH
156. Scale and Shift panel is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics X Axis Scale and Shift r Y Axis Scale and Shift cale 1 0 cale fi O Horizontal shift after scale p Vertical shift after scale Shift values to zero out first value Shift values to zero out first value Additional shift n0 Qu shit 0 0 l Scale Scale factor applied to the x or y axis values Shift values to zero out first value For the x axis shift the curve horizontally such that its first x value becomes zero For the y axis shift the curve vertically such that its first y value becomes zero Additional shift Additional horizontal vertical shift i e in addition to the zero out operation if applied in the curve s x y values 7 14 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs NENNEN NOTE Scaling the y axis of a curve will affect the results of fatique damage calculations See Section 7 2 10 Fatigue calculation from standard S N curves 7 2 8 Appearance The Curve appearance can be altered by selecting the Appearance tab in the curve s Property Editor panel The associated panel is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics r General appearance Symbols 1 Curve type 0 ies o Symbol type o Noe gt Symbol size o b g Curve color 2 mBsck Num symbols 5 po a AI Q curve Type
157. The Xw Yw plane is the tangent plane of the road in the contact point C The camber angle is defined by the inclination angle between the wheel plane and the normal nr to the road plane x y plane Units Next to the convention to the TYDEX W axis system all units of the parameters and variables used in MF Tyre agree to the SI units In Table A 2 provides an overview of the most important parameters and variables see also Section A 10 Definitions Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 4 Axis Systems and Definitions se Table A 2 SI Units Used in MF Tyre Variable Type Name Abbreviation Unit angle slip angle a rad camber angle y force longitudinal force Fy N lateral force Fy vertical load Fz overturning moment Mx Nm rolling resistance moment My self aligning moment M speed longitudinal speed Vx m s lateral speed Vy longitudinal slip speed Vox lateral slip speed Vsy rotational speed tire rolling speed Q rad s A 4 3 The Contact Point C and the Normal Load The radius of curvature of the road profile is considered large as compared to the radius of the tire The tire is assumed to have only a single contact point C with the road profile Furthermore for calculating the motion of the tire relative to the road the road is approximated by its tangent plane at the point on the road below the wheel centre see Figure A 4
158. This requires the blocks Transfer Fcn Gain and Sum as shown in Fedem Release 5 0 User s Guide 5 11 5 Control System Modeling 5 5 External control systems Ve the figure below There are two inputs reference and measurement and one output called ctrlOut etilOut Transfer Fon To Workspace reference From Workspace Gain measurement From Workspacet 5 5 3 Connecting Simulink models The interface to an external control system is created in a right click pop up a Zoom To t Spring characteristics menu in the Model Manager see Sort by ID Hj Damper characteristics illustration The empty object will then Sort by Name R Friction 5 appear under the External Control Delete Del Function Systems group F Time history input file 4 Road elevation In the Property Editor panel you may External Control System now specify the Simulink file containing the external model see below amp File Reference The Simulink file is parsed by Fedem in order to find the input and output of the model In the example below reference and measurement were found The user must then specify the functions to be connected to these From Workspace blocks Simulink file p eua Browse 3 Wanted position Function 4 Position measurement Function Detected To Workspace blocks are taken as outputs An External Ctrl Sys Sensor which is available for referenci
159. User s Guide Release 5 0 Trondheim April 2009 Copyright 1995 2009 by Fedem Technology AS Published 2009 Printed in Norway All rights reserved No part of this document may be reproduced in any form or distributed in any way without prior written permission from Fedem Technology AS The information provided in this document is subject to change without notice The Software described in this document is furnished under a license agreement The software may be used or copied only under the terms of the license agreement which accompanies the software Fedem is a registered trademark of Fedem Technology AS Acrobat Reader is a registered trademark of Adobe Systems Inc Altair and Hypermesh are registered trademarks of Altair Engineering Inc I DEAS is a registered trademark of Structural Dynamics Research Corporation MATLAB and Simulink are registered trademarks of The MathWorks Inc MATRIXx is a registered trademark of Wind River Systems Inc MSC Nastran is a registered trademark of The MSC Software Corporation MSC Patran is a registered trademark of The MSC Software Corporation Nastran is a registered trademark of NASA OpenGL is a registered trademarks of Silicon Graphics Inc Pro ENGINEER is a registered trademark of Parametric Technology Corporation All other brand or product names mentioned herein are trademarks or registered trademarks of their respective companies or organizations Fedem Technology A
160. X dbvx See Equation B 10 Change of in plane belt translation frequency with speed Q_BVT dbvq See Equation B 11 Change of wind up belt rotation frequency with speed Fedem Release 5 0 User s Guide B 27 B Using the SWIFT Tyre Model B 5 Tire Property File Example B 5 Tire Property File Example FILE TYPE a Vea FILE VERSION 3 4 0 FILE FORMAT ASCII l TIRE VERSION SWIFT Tyre 1 0 COMMENT New File Format v3 0 COMMENT Tire 205 60 R15 COMMENT Manufacturer DELFT TYRE COMMENT Nom section with m 0 205 COMMENT Nom aspect ratio 60 COMMENT Infl pressure Pa 220000 COMMENT Rim radius m 0 19 COMMENT Measurement ID DELFT TYRE COMMENT Test speed m s 16 667 COMMENT Road surface Asphalt COMMENT Road condition Dry l FILE FORMA i ASCII USER MF Tool Generated by TNO Copyright TNO Tue Aug 07 16 33 34 2001 USE MODE specifies the type of calculation performed 0 Fz only no Magic Formula evaluation 1 Fx My only 2 Fy Mx Mz only 3 Fx Fy Mx My Mz uncombined force moment calculation 4 Fx Fy Mx My Mz combined force moment calculation 10 including relaxation behaviour 20 including rigid ring dynamics 1 mirroring of tyre characteristics example USE MODE 12 implies calculation of Fy Mx Mz only including relaxation effects mirrored tyre characteristics
161. a command It will tell you what you are expected to do during the different steps of the command It also provides a Done and a Cancel button used to accept choices or to cancel the command Workspace area contains the Modeler Control Editor and Graph View windows for constructing and viewing models and results ID and Topology panel contains a list of objects related to the selected item Property panel allows you to view and edit the properties of individual objects in your model eo Status bar provides information of the status progress information and whether some solver is running 2 5 2 Menus and toolbars Fedem commands are initiated from buttons on the toolbars and menus All Fedem commands can be accessed from the menus while the toolbars display only some of the most commonly used commands The menus are arranged from left to right in logical order of task performance starting with standard file functions then continuing with viewing commands mechanism modeling control system modeling analysis solution tools and finally results management Command sensitivity Menu and toolbar buttons are sensitive to the active window and object selection For example if an object in the modeling window is selected the graph view controls appear dimmed grayed out and cannot be selected Fedem toolbars Fedem uses the following toolbars a toolbar handle to the left or on top marks the beginning of
162. a rough indication on the states of the faces is given To see the exact top and bottom of every face on a link set the detail level to Surface or Surface and Internals This is off by default Perspective To display a perspective view of your mechanism click the Perspective button This command controls the appearance of mechanisms in depth as perceived by normal binocular vision m Parallel Projection To display a parallel view of your mechanism click the Parallel Projection button This is the default projection 2 7 3 Zoom and Pan Fedem provides zooming and panning controls for use in the active view for example graph views The following commands can be accessed on the Zoom and Pan toolbar or View menu 2 22 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 7 Visualizing the model NOTE Some of these commands cannot be used in all windows When commands cannot be used in the current view their buttons become unavailable grayed out on the menus and toolbars Zoom All To scale the active view so that all objects for graph views every curve on the graph fit within the view press the Zoom All button When working in graph views this can also be achieved by pressing the F5 key Zoom To This command pops up the correct view zooms to the selected object and places the Dynamic Center of rotation at the center of the object This is very useful when trying to locate a certain triad or joint in
163. above convergence criteria have different dimension properties Some are dimensionless whereas others depend on the model units The default values defined are suitable for the SI unit set If you model in a different unit set see Section 3 9 Model preferences you will need to adjust some of your active tolerance values accordingly The scaled vector norm of the displacement correction is dimensionless whereas the same norm for the velocity correction has dimension 1 time and for the force residual it is force length The Max norms have the dimension corresponding to the quantity that they measure For more information about convergence criteria see the Fedem R5 0 Theory Guide Section 7 2 1 Convergence criteria Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis Eigenmode tab You can set up the calculation of eigenmode solutions see Modal analysis in Section 6 1 2 by adjusting the following parameters o This option allows you to Dynamics Solver Setup DER enable disable calculation of the eigenmode solutions Time Integration Tolerances You can specify the number odes to of eigenmodes to be Same a TENE computed genvalue shift H2 You can specify the time interval between each eigenvalue analysis You can specify an Eigenmode Shift see the Fedem R5 0 Theory Guide Section 9 6 3 Using shift when solving the eigenvalue problem You can enable disable the a
164. all computed time steps between the specified start and stop time will be considered The Reset button restores the default Time Interval values which are equal to the start and stop times of the simulation as specified in the Dynamics Solver Setup and to use all time steps in between 2 You may limit the number of elements to be processed concurrently by adjusting this value Especially for large links and long time series this might be necessary due to higher memory requirements Fedem Release 5 0 User s Guide DoR Strain Coat Recovery Summary Setup Time Interval Stat 00 Stop 1 6 Increment 0 01 MV Use all time steps Reset G PS tax number of elements processed together 2000 n I Biaxiality stress threshold 20 Rainflow Fatigue Analysis M iv Perform rainflow and fatigue analysis Signed abs max stress S N xl L D Analysis type Stress range threshold 10 0 Histogram Number of bins e4 Initial range Max OK Apply Cancel 6 41 6 Mechanism Analysis 6 9 Strain coat analysis E You may set a gate value for the Biaxiality calculation That is the mean biaxiality will be computed only for elements whose max principal stress is larger than the specified threshold value You may toggle on off rainflow and fatigue analysis The remaining options in this window are sensitive only when this toggle is on Q When using the default
165. allows you to replace the FE model of the link with a new one The button triggers a file dialog in which the new link file can be chosen Note that all mechanism entities attached to the link that do not have corresponding nodal points in the new FE model will be detached Needs reduction FE Parts only This label is a flag that signals if your FE model has been reduced or not If some data for the reduced link is present and is recognized to match the link this entry will read Reduced n where n is a number referring to the directory in the link database containing the reduced matrices Structural Damping Allows you to change the values of both the mass and stiffness proportional damping for the link These parameters are described in the Fedem R5 0 Theory Guide Section 7 5 Structural damping Scaling of dynamic properties Allows you to scale stiffness and mass of each individual link in the dynamics simulation The scaling is done during initialization and stays in effect for the entire analysis This option is useful for sensitivity studies of deflection and stiffness WARNING The mass and stiffness scaling is not accounted for in any of the recovery analyses and the recovered result will thus be misleading on FE links using mass and or stiffness scaling WARNING The damping matrix and the associated force vector are not affected by the mass and stiffness scaling parameters That is when using mass and or stiff
166. and settings for this codec Be aware that some codecs may not work this is dependent on your system configuration The codecs that seem to have the best success rate is MS Video 1 Cinepak by Radius and the DivX codec If you don t have a DivX codec installed on your machine you can get it from the DivX home page http www divx com Fedem Release 5 0 User s Guide 8 Managing Results Es Chapter8 Managing Results A Fedem simulation can generate large amounts of data This chapter explains the concept of the Fedem Results Data Base RDB how to manage the data files and some information on how Fedem stores and handles the data Sections in this chapter address the following topics Model and Result file handling gt Result File Browser gt RDB directory structure Fedem Release 5 0 User s Guide 8 1 8 Managing Results 8 1 Model and Result file handling 8 1 Model and Result file handling A Fedem model consists of the mechanism model file the FE model files and all the generated result data files The generated results can be divided into three main groups FE model reduction data Dynamics response data FE recovery data Normally all these groups can be looked upon as one single model even though it is spread across several files and directories Fedem keeps track of which files that are part of your saved model and which are not Because the solvers write their data directly to disk while solv
167. and CMASS may exist without any associated properties PBUSHCOEFF and PMASS respectively inthe t 1 file Such elements are created automatically by Fedem during modelling e g when a mechanism joint is attached to a slave FE node in a Link see Section 3 6 Attaching and detaching elements When the Fedem Link Reducer encounters such property less elements some stiffness mass properties are computed automatically for these elements based on the assembled stiffness mass matrix of the whole Link such that the element can be regarded as nearly mass less and rigid Refer to the Fedem R5 0 Theory Guide Appendix A Finite Element library for details on this computation Parameters for element statements are given in the table below Parameter Description id External element identifier ni Reference to the ith node connected to this element bcid Reference to a stiffness coefficient field for bushing elements beid Reference to an eccentricity field for bushing ele ments bpid Reference to a pin flag field for beam elements csid Reference to a local coordinate system field eid Reference to an eccentricity field for beam elements C4 Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format es Parameter Description gid Reference to a geometric property field for beam and shell elements lid Reference to an effective length field for beam e
168. and Dampers options for defining the non linear behavior of a spring The Property Editor panel for the advanced spring characteristics is displayed below Spring function p 9 z4 Translation spring Constant stiffness Failure criterions e Max Deflection o 0 Max Force fp 0 Min Deflection o MinForce fp 0 Yield criterion Max Yield Force o 0 l Min Yield Force 0 0 Y Wa Max Yield Deflection o 0 Q spring function In this field you may either enter a constant spring stiffness or select an existing basic spring characteristics function from the pull down menu Failure criterions Failure of the spring can be defined through max and min forces and deflections You can enable all four criterions 4 and whichever failure criterion is satisfied first will switch the spring permanently off i e both spring force and stiffness vanishes Max Deflection Spring is active until its deflection becomes greater than this value Min Deflection Spring is active until its deflection becomes less than this value Max Force Spring is active until force becomes greater than this value Min Force Spring is active until force becomes less than this value Yield criterion Hysteretic behavior and or permanent deflection after unloading can be introduced in springs by this options The yield criterion will limit the force of the
169. and exporting Triads can generally not be detached or deleted from the unloaded link This is done to protect the reduced matrices from being accidentally invalidated If you try to remove or detach a triad on an unloaded link you will get an error When detaching joints from an unloaded link a triad will be left on the link where the joint was attached 2 9 4 Postprocessing unloaded links Unloaded links will be completely skipped when loading an animation except for the rigid body motion This makes it possible to focus the computer resources on the parts of your model that are interesting and skip everything else see also Disabling and Enabling results in Section 8 2 2 2 4 0 Printing and exporting 2 10 1 Printing The Print View command is available only for graph views Clicking the amp b Print View button prints the active graph view from the Workspace area regardless of the selection in the Model Manager panel 2 10 2 Exporting Six types of objects can be exported from Fedem links FE models individual curves graphs graph views the 3D modeler view and animations Links can be exported in Fedem s ft 1 format Curves and graphs can be exported in ASCII asc txt nCode DAC dac or MTS RPC time history rsp drv tim format gt Graph views and the 3D modeler view can be exported as binary image files in a variety of formats gt Animations can be exported as movies in mpeg 1 mpeg
170. anel you may also find some information on the link s underlying FE model by selecting the link in the Result File Browser see Section 8 2 1 The Result File Browser dialog The link properties are separated into several tabs to better organize the different settings The number of tabs and their content depend on whether the link is defined as a Generic Part or an FE Part or if it is a link used for visualization only grounded links The different tabs are as follows Part tab Always present Origin tab Always present Reduction Options tab Present for FE Parts not for grounded links Reduced Loads tab Present for FE Parts if element or nodal point loads are present in the FE data file not for grounded links CoG tab Present for Generic Parts only not for grounded links Mass tab Present for Generic Parts only not for grounded links Stiffness tab Present for Generic Parts only not for grounded links Hydrodynamics tab Always present unless the link is grounded VVVVVY YVVYNYY Advanced tab Always present unless the link is grounded 4 6 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links Part tab The Part tab displays some basic settings and information about the link The actual options that are displayed depend on whether the link is a Generic Part an FE Part or if it is used for visualization only Below three versions of this panel are displayed Part Orig
171. anslation then in rotation about a point and lastly rotation about the remaining axis The object is then locked in place See also Movability in Section 3 5 IMPORTANT Stickers function as modeling aids only They are not considered part of the mechanism model and therefore do not influence the mechanism motion during simulation Manually applying stickers Stickers are created automatically when using Smart Move but you can also create them manually when you need a certain type of movability To rotate about a point in space apply one sticker at the rotation center To rotate about an axis apply two stickers somewhere along the rotation 3 6 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 4 Creating mechanism elements PX 3 4 axis Stickers are applied to Triads and Links and can be positioned at any point in space They are not restricted to the geometry of visualization or the nodal points of a link To create a sticker perform the following steps 1 Click the Sticker button on the Mechanism Tools toolbar The Guide bar prompts you to select an application point for the sticker on an object Place the cursor over the point on the object you want and press the left mouse button The selection snaps to the nearest node or point on the object If necessary edit the position using the Interactive Odometer as described in Section 3 3 2 Interactive Odometer and 3D Point Marker Confirm the point by
172. are several different sets of viewpoint control commands Mid mouse button wheel mouse motion Function keys F1 F2 F3 and F4 mouse motion Keyboard keys Predefined view tool buttons B Middle mouse button wheel Pressing and holding the middle mouse button while moving the mouse will rotate the view around the rotation center If the button was pressed near the edge of the 3D view the rotation will be restricted to the viewport s normal axis Rolling the mouse wheel will zoom in and out When the mouse wheel is used to zoom in the view will be zoomed towards the position of the mouse pointer giving a combined zoom and pan behavior Using the middle mouse button commands is the most used 3D navigation in Fedem Function keys The function key based navigation can be used when you need added control over the navigation The commands include Pan F1 Zoom LS F2 Rotate 45 F3 Select Rotation Center e F4 These functions are often useful while working in the Modeler We recommend that you keep your left hand near these function keys while you work To use the function key commands press and hold the function key and move the mouse to manipulate the view The manipulation will only Fedem Release 5 0 User s Guide 2 19 2 Learning the Basics 2 7 Visualizing the model 2 20 occur as long as the mouse is inside the Modeler view By pressing the left mouse button you may avo
173. ase 5 0 User s Guide 2 Learning the Basics 2 11 License information 2 1 2 11 1 Exporting animations Animations can be exported using the mpeg 1 mpeg 2 and avi Windows only formats The animation may be viewed in any standard video player e g Windows Media Player or Elecard MPEG Player www elecard com Note that the Windows Media Player has a size limit of 720x480 pixels After loading the animation Set model link repository Print View Print View Setup C New Ctrl N gt Open Ctrl 0 E Save Ctrl 5 Save As Vm ChrltL Exit Ctrl Q Export Object Export View select Export gt Export Animation from the File menu to open a file dialog where you can select location file name and format of your exported animation See also Section 7 4 4 Exporting animations License information The Fedem software consists of a foundation module and several add on modules The actually installed and available modules depend on your license contract with Fedem Technology Available modules The currently installed licenses are listed to the console window when Fedem is started if the command line option licenseinfo is specified The list may also be printed in the Output List at any time during a Fedem session by selecting the License Information entry in the Help menu The list indicates the licenses that are required upon startup and the add on licenses tha
174. ate Magic Formula Table A 11 Aligning Coefficients Pure Slip Name used in tire Name property file Explanation Gpze QDZ6 Peak residual torque Dmr Dmr Fz RO Gpz7 QDZ7 Variation of peak factor Dmr with load pz QDZ8 Variation of peak factor Dmr with camber dpz9 QDZ9 Variation of peak factor Dmr with camber and load qEz1 QEZ1 Trail curvature Ept at Fznom qEz2 QEZ2 Variation of curvature Ept with load qEz3 QEZ3 Variation of curvature Ept with load squared GEz4 QEZA Variation of curvature Ept with sign of Alpha t qEz5 QEZ5 Variation of Ept with camber and sign Alpha t quz1 QHZ1 Trail horizontal shift Sht at Fznom duz2 QHZ2 Variation of shift Sht with load qduz3 QHZ3 Variation of shift Sht with camber qHz4 QHZ4 Variation of shift Sht with camber and load Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula pc A 6 2 Magic Formula Steady State Combined Slip Figure A 12 Combined Slip Condition Combined Braking Traction and Cornering Formula Longitudinal Slip Combined Slip F F y Grala K F A 56 with Gy a weighting function We write F D 4c0s C arctan B 4o E B 0 arctan B 0 A 57 a Qt Su A 58 with coefficients B rg 4 COS arctan rg x 5 hyo A 59 Cra Text A 60 Ts Dsa cos C arctan B Sma En Bou arctan B S 1 USB Eya Vex Exod A 62 Fe
175. ating their topological relationships This list can then be used to investigate these related objects and to browse through the mechanism model through the topological connections This can be done by using the browsing features offered by the Topology View described below Temporary highlight The items in the topology view will be highlighted in the Modeler when you select an item keeping the mouse button pressed This is useful to see exactly which objects in the 3D view that corresponds to the listed item Right clicking an item in the list will show a tiny pop up Zoom To menu that allows you to either Zoom to or Select the item ne elec Zoom To This command zooms to the item making it easy to locate it in a complex model See also Section 2 7 3 Zoom and n Pan Select This command will select the right clicked element from the topology view and thus jump to it showing the properties of that item instead See also Section 2 6 1 Select on how to get back to your previous selection TIP Double clicking an item in the topology view will also select it Fedem Release 5 0 User s Guide 2 11 2 Learning the Basics 2 5 Touring the interface 2 5 5 Property Editor The Property Editor panel is used to view and edit the properties of mechanism items The appearance of properties is different depending on the object selected The image below is an example showing properties that are common to some of the Fedem modeling
176. atrix in core consolemsg Output error messages to console false cwd Change working directory damped Complex modes are calculated false datacheck Do data check only exiting after data false input debug Debug print switch 0 double Save all results in double precision false eigfile Name of eigenvector file energy_density Save scaled strain energy density false fao Read additional options from this file fco Read calculation options from this file fop Read output options from this file frsfile Name of solver results database file fsifile Name of solver input file fedem solver fsi help Print out this help text false licenseinfo Print out license information at startup false licensepath licensepath linkId Link base ID number 0 linkfile Name of link input file rdbfile Name of modes results database file rdbinc Increment number for the results data 1 base file recover_modes List of mode numbers to expand resfile Name of result output file samfile Name of SAM data file terminal File unit number for terminal output 6 version Print out program version false Fedem Release 5 0 User s Guide E Command line options E 5 Mode shape recovery options fedem_modes Command line option Description Default value VTFdscale Deformation scaling factor for VTF output 1 VTFexpress Write express VTF files
177. axis Euler angle parametrization Rotational vector Singularity free Rodriguez parametrization See the Fedem R5 0 Theory Guide Section 2 3 Finite rotations for further details on these choices You may alter the update sequence of the Euler angle parameters The default sequence is Z Y X CAUTION The Sequential rotation formulation may lead to singularities in the rotation update computations if the joint undergoes a 90 degrees rotation about the local Y axis If you have such behavior in the joint you must use the Rotational vector formulation to achieve proper results You may specify how the translational and rotational joint springs should be inter connected Cylindrical or Spherical coordinates This can be used to describe the cylindrical or spherical behavior of rubber bushings or pin joints with clearances If you want the spring characteristics in the joint variables to be interpolated resulting ina cylindrical spherical behavior select the proper setting from the drop down menu Please refer to the Fedem R5 0 Theory Guide Section 5 1 1 Interconnected Spring Elements for details on how this affects the stiffness matrix Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints NENNEN 4 4 3 Point to point joints With point to point joints the motion constraints of t the joint are applied between two points represented amp u gt by the slave and the master triad with their amp
178. basic function see Figure B 12 The distance between the two points is indicated as the shift of the basic function The distance between the points imp depends on the contact length as is displayed in Figure 4 28 of 1 and the shift is calculated using Equation B 29 2 iig 2 9rimp1 sat Timp2 sa B 29 Both the contact length and the shift of the basic function are displayed in Figure B 12 Fedem Release 5 0 User s Guide B 17 B Using the SWIFT Tyre Model B 3 Force Evaluation Figure B 12 Contact Length and Shift of the Basic Function as Function of Load 0 4 p b tyre radius Contact length 2a 0 2 Basic function shift Normalised contact dimension 1 0 0 5 1 y 5 2 Normalised vertical load 1 nominal load This method of effective inputs can not only be used for discrete obstacles but also for measured road data having a random character Figure B 13 gives an illustration In this example the road height is specified every 0 1 meter Using the stepwise changes in road height the basic functions can be calculated and using the two point tire road interface model finally the effective road height is obtained The SWIFT Tyre model samples the road using a fixed interval This value is specified by ROAD INCREMENT in the MODEL section of the tire property file as seen on page B 29 Typically this value is in the range of 0 1 0 2 meter or larger val
179. below D esciiption Ti 1005000 Td Joo iets p Ts a i CAUTION Changing a value in the Property Editor does not automatically apply the change You must press the Enter key after editing each value to apply the change Connecting blocks Once you have placed blocks in the Control Editor you must draw connection lines between them to define the control module shown at right To connect two control blocks in your control module complete the following steps Click and drag from the arrow output of one control block to the circle input of another block and release the mouse button A connection line is drawn between the two blocks You can adjust the path of the line by dragging and dropping the line Click and drag either a corner or a line segment between the corners Adding break points This command adds lines or breaking points to connection lines To use it click the Add Breakpoint button on the Control Tools toolbar then click and drag an existing line A new corner is created 5 Control System Modeling 5 4 Building control modules 5 4 6 L1 5 4 7 5 10 Removing break points This command removes lines or breaking points on connection lines To use it click the Remove Breakpoint button on the Control Tools toolbar then select one of the break points on a line Press Done to confirm the selection NOTE A line consists of at least three perpendicular
180. ble A 6 Scaling Coefficient Pure Slip Name Soper file tire Explanation Irzo LFZO Scale factor of nominal rated load lex LCX Scale factor of Fx shape factor lix LMUX Scale factor of Fx peak friction coefficient Nex LEX Scale factor of Fx curvature factor Axx LKX Scale factor of Fx slip stiffness ux LHX Scale factor of Fx horizontal shift Ayx LVX Scale factor of Fx vertical shift gx LGAX Scale factor of camber for Fx cy LCY Scale factor of Fy shape factor Amy LMUY Scale factor of Fy peak friction coefficient Aey LEY Scale factor of Fy curvature factor Aky LKY Scale factor of Fy cornering stiffness Ahy LHY Scale factor of Fy horizontal shift Ayy LVY Scale factor of Fy vertical shift Ayy LGAY Scale factor of camber for Fy Ae LTR Scale factor of Peak of pneumatic trail Amr LRES Scale factor for offset of residual torque yz LGAZ Scale factor of camber for Mz mx LMX Scale factor of overturning couple wx LVMX Scale factor of Mx vertical shift Amy LMY Scale factor of rolling resistance torque A 16 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre Table A 7 Scaling Coefficients Combined Slip Name used in tire Name property file Explanation Axa LXAL Scale factor of alpha influence on Fx Awe LYKA Scale factor of alpha influence on Fx Avy LVYKA Scale factor of kappa induced Fy As LS Scale factor of Moment arm of Fx Table A 8 Scaling Coef
181. ble Save all results in double precision false dumpDefNas Save deformations to Nastran bulk data false files eigfile Name of eigenvector file fao Read additional options from this file fco Read calculation options from this file fop Read output options from this file frsfile Name of solver results database file fsifile Name of solver input file fedem solver fsi group List of element groups to do calculations for help Print out this help text false licenseinfo Print out license information at startup false licensepath License file directory linkId Link base ID number 0 linkfile Name of link input file maxPStrain Save max principal strain to results data false base maxPStress Save max principal stress to results data false base maxSStrain Save max shear strain to results database false maxSStress Save max shear stress to results database false minPStrain pa min principal strain to results data false ase E 12 Fedem Release 5 0 User s Guide E Command line options E 4 Stress recovery options fedem_stress Command line option Description Default value minPStress Save min principal stress to results data false base nodalForces Compute and print nodal forces false rdbfile Name of stress results database file rdbinc Increment number for the results data 1 base file
182. ble clicking on the entry in the Topology List but the normal way of editing their properties is through the DOF tabs in the Joint property panel see Joint variable properties below 4 4 2 Joint properties You can select a joint to display its properties in the Property Editor panel shown below for a Revolute joint The Property Editor panel for a joint consists of one tab with a summary table of all the major joint properties and additional tabs for each of the joint variables where their properties are displayed in detail The summary table shows a non editable summary of all joint variables along with other editable joint properties Finally there is an Origin tab for the point to point joint types Rigid Revolute Ball and Free joints and an Advanced tab with further properties for Ball and Free joints Fedem Release 5 0 User s Guide 4 21 4 Mechanism Elements 4 4 Joints 4 22 Since the number of joint variables depends on the joint type you may see from zero Rigid joint to six Free joint sets of joint variables listed in the summary table and a similar number of joint variable tabs 1 Summary 2 4 T2 Rz CTm mm H Free 0 0 0 0 Re Free 00 00 Friction 1 None X E IV Z translation DOF 1 Summary tab This tab displays a Summary table over all properties of the joint Origin tab This tab contains the definition of the joint coordinate system i e the
183. ble element faces visible 1 means visible element faces Loads Both concentrated point loads on nodes and distributed surface loads on shell and solid elements are supported The FTL syntax is as follows CFORCE sid fx fy fz ni CMOMENT sid mx my mz ni SURFLOAD sid pl n lt n gt n lt n gt p lt n gt el e n PORIENT oid FACELOAD sid pl p n el f1 e n f n PORIENT oid Parameter Value Type Description sid Integer Load set identifier fx fy fz Real Global force and torque components mx my mz Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format C 1 6 C 1 7 Parameter Value Type Description p lt i gt Real Surface force intensity in local node i n lt i gt Integer Node IDs of load target points e lt i gt Integer Element ID f lt i gt Integer Local face number Strain Coat Elements Two Strain coat element types are supported where the type names reflect the number of element nodes The FTL syntax is as follows STRCT3 id n n2 n3 PSTRC pid1 FE eid STRCQ4 id n1 n2 n3 n4 PSTRC pidi PSTRC pid n PSTRC pid lt n gt FE eid Parameter Description id External element identifier n lt i gt Reference to the ith node connected to this element pid i Reference to the property field of the i th calcula tion point for this element eid Reference to the underly
184. c Press the menu button to access the list 2 12 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 5 Touring the interface S 2 5 6 Fedem Release 5 0 User s Guide By pressing the Edit button you will select the item shown in the menu as if you had selected it in the Model Manager This is a convenient way of navigating through the relations of the model giving a simple way of finding the details of a complex model In some property fields a numeric value can be entered instead of selecting a reference from the menu The spring stiffness property is a good example Entering a numeric value will assign that value as a constant spring stiffness to the spring in question TIP Property menus that accepts a numeric value always have a numeric value as default while None is normally the default for Property menus not accepting a number To change a property from referring to constant select the top entry in the pull down list which is either None or the last numerical value that was entered in the same box or delete the current contents of the box type in a numerical value and then press Enter to apply the change Workspace The Workspace area is used for constructing manipulating and viewing mechanism models control systems graphed results and animations The Workspace can contain several windows including the Modeler Control Editor and multiple windows for viewing graphed results These
185. calculation intervals are different If you select Only for requested results then only intervals shown are those at which the stress is calculated both stress contours and motion appear continuous Contours tab If you selected Load face contours and or Load line contours in the Property Editor you can display color contours on the mechanism Fedem Release 5 0 User s Guide 7 25 7 Postprocessing Results 7 3 Animations e assembly during the animation for Time History and Time Summary animations only You must then specify the values to be used for the color contours on the Contours tab shown below in the Property Editor panel before loading the animation The Contours tab is not available for Eigen Mode animation Time Contours r Contour Value o Averaging Result class Element node No averaging Result Von Mises stress C Do average Opts Operation None X Result Set r Multiple Face Results o By operation Absolute Max x C Byname Top 7 peration Absolute Max v Contour Value These options are used to select the results that will be displayed as color contours Result class this option allows selection of the FE entities for which you want to show color contours You can select either nodes elements one single result for each element or element nodes one result for each node within an element This selection controls the options for the Result and Value settings s
186. case the last save operation failed due to full disk or other reasons NOTE The previous version of the model file will be renamed to lt filename gt bak E To save the file in a different location and or with a different name choose Save As in the File menu When saving a copy of the file using Save As you can choose to discard results and or reduced link information by setting the toggles in the Save As dialog Save model file as x Look in E Fedem Fedem Models 23 1_TNO_MF Tyre Input_Files t Ex Q TE b01 04 fmm EP b01 11 mm E 03 22 fmm 03401 RDB SB 1b01x05 fmm P bO1x12 fmm b03x22_ADB BH bN1x06 fmm E b03x01 fmm C3 Repository a cal bO1 x07 fram ical b03x02 fram bOI xO1 fmm bO1xO8 tmm EP b03x11 fmm bo x02 fmm Be bO1xOS tmm E b03x12 fmm TE bOlx03 mm BH bO1x10 fmm TE b03x21 fmm File name Loader fmm File type Fedem model file frm z Cancel Discard results Discard reduced links When saving a new model for the first time you are prompted to give it a name different from the default name untitled f fmm which was assigned when Fedem was started see Section 2 4 Starting Fedem If you also have performed some solver tasks before saving the model the existing results database will then be moved to the correct location associated with the new model file name Fedem Release 5 0 User s Guide 2 31 2 Learning the Basics 2 9 Loading and unl
187. ced by FE Fatigue and Duty Cycle VVVYYVYV Damage Log Damage Life repeats Log Life repeats Life equnits Log Life equnits Interpretation of shear strains in contour plots The stress or strain state at a point in the model can be represented as a second order tensor in a mathematical setting i e in the 2D case we have Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 3 Animations Sey o Oxx Oxy and eu xy Gyx Oyy Esx yy where equilibrium in angular momentum requires The strain x Opx components are defined as u t uj 2 where uis deformation and the indices i and j both run i through xand y x y and zin 3D The advantage of this representation is that computation of von Mises and principal quantities can be performed using the same piece of code for stress and strain thereby making the implementation more general and robust An alternative representation more common to engineers is by means of the stress and strain vectors i e in 2D we have Oxx XX o and Oyy Eyy Oxy Yxy where y Eyy t Epy Uy y t uy andthus y 2 The results from a stress recovery analysis that may be visualized in an animation are based on the tensorial strain representation i e the shear strain components including Max Shear are equivalent to the term and not Yay However the Max Shear strain quantity computed from the Strain Coat recover
188. cifying a discrete point 3 12 using with Smart Move command 3 5 intermediate file types D 3 isometric button 2 21 item type 2 11 iteration step size 6 25 Iteration step size limit 6 24 J joint variables 4 21 joint pairs 4 37 Joint Variables 4 20 joint variables 4 22 joints about 4 20 adding friction 4 22 adding motion constraints 4 24 attaching 3 16 attaching multiple 3 17 attaching to links 4 20 attachment restrictions 3 16 ball 4 27 cam 4 33 cylindric 4 32 detaching 3 21 free 4 27 friction 4 38 master and slave 3 16 pair constraints rack and pinion 4 38 point to path 4 30 point to point 4 27 prismatic 4 30 revolute 4 27 rigid 4 27 summary table 4 25 triad connections 4 20 K Kinematics described for MF Tyre A 36 L left view 2 22 License 2 39 limiter block 5 6 line view 2 22 lines definition 5 10 lines item appearance 2 28 Link coordinate system 4 3 Link Database 4 14 link files Fedem Release 5 0 User s Guide directory 2 3 8 1 mechanism analyses 2 8 link reduction files 6 48 speeding up 6 2 link repository 4 14 Mechanism Creation toolbar 3 4 Link_DB directory 2 3 mechanism elements 3 1 subdirectories 8 9 attaching to a link 3 16 link_DB directory 8 9 constrained by cylindrical joint 3 11 links 1 4 3 8 constrained by prismatic joints 3 11 about 4 2 creating 2 8 3 8 applied forces 4 46 customizing 4 1 as masters and slaves 4 20 de
189. clicking Done The sticker is created and the sticker symbol appears in the Modeler window at the selected point Deleting stickers You can delete stickers individually or all in a single operation gt To delete a single sticker complete the following steps 1 Select the sticker you want to delete in the Modeler window or from the Model Manager Objects list The sticker symbol in the Modeler turns red when selected 2 Click the Delete button on the Standard toolbar or use the Delete key The sticker is removed from the model To delete all the stickers applied to your model click the Delete All Stickers button on the Mechanism Tools toolbar or the Mechanism menu NOTE You may have to click and hold down the Sticker button on the Mechanism Tools toolbar to access the Delete All Stickers command WARNING There is no undo option after deleting all stickers To replace them in your model you must recreate each of them individually Creating mechanism elements Objects such as Spring Damper characteristics Functions and Frictions which do not need to be positioned are created in the Model Manager Objects list Right click an empty space in the Model Manager panel and select Create to access the full list of elements that can be created using the shortcut menu Fedem Release 5 0 User s Guide 3 7 3 Mechanism Modeling 3 4 Creating mechanism elements All mechanism elements that need to be positioned in the Fedem m
190. contains several large FE models unloading some of the FE data from memory can be necessary to in order to reduce the amount of resources used This is particularly useful when you want to load contour plots for a particular link or to free up resources for the solvers 2 9 1 FE Data Settings Lat Finite Element models tend to be Tee large The amount of data needed for 4 Tuk Status visualization and lookup is indeed Front Not Loaded significant In some cases it will be ipo EL 3 Bucket Loaded convenient or necessary to unload 4l Bel Crank Loaded this data to free up RAM To control 5 Bucket Link Loaded the loading and unloading of FE data the FE Data Settings dialog is used 2 32 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 9 Loading and unloading FE Data NENNEN To open the dialog select the FE Data Settings command in the Tools menu The status of each link is set using the drop down menu in the Status column Set the status you want for each link and press OK or Apply The links that are not loaded will be shown using the Simplified line shape as described in Section 2 7 5 Item Appearance The loading and unloading of links does not affect the simulation The solver processes will read the necessary FE Data from the FE model files NOTE Loading unloaded links can take several minutes if the links are big TIP To change the status of all or several links
191. ct the triad to a set of existing FE nodes 9 You can move the triads to the correct positions Update the FE mesh with nodes at the correct positions Turn the FE link into a Generic Part Delete the Triads 3 7 Deleting mechanism elements Fedem uses the Delete command to remove mechanism elements from a model The Delete command can be used in two different ways in the Modeler window or in the Model Manager panel 3 7 1 Deleting in the Modeler To delete elements in the Modeler window complete the following steps 1 In the Modeler window select the element to be deleted or hold down the Ctr key and select multiple items The selected items are highlighted in red in the Modeler window rs 2 Toremove the selected element s from the model click the Delete button on the Standard toolbar or hit the Delete key WARNING There is no undo option after deleting objects To replace mechanism elements after deleting them you must recreate each of them individually 3 7 2 Deleting in the Model Manager To delete mechanism elements in the Model Manager panel complete the following steps 1 In the Objects list select the item to be deleted or hold down the Shift or Ctrl key and select multiple items The selected items are highlighted in red in the Modeler window TIP You can also click and drag the cursor to select multiple items for deletion 3 22 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 8 Usin
192. ction 7 2 5 Curve properties Spring Damper Summary Origin Tz Rz Constraint Type Stress free angle control Spring properties C Fixed A p Angle in model eo 0 oo M Wi Free Scale None g C Prescribed C Init stress free angle fo 0 Spring Damper Load magnitude Stress free angle change Scale None E F 0 Zi None zd Use deformational velocity km properties Init deflection 0 0 00 i These options enable you to add elastic and damping behavior to the joint variable by entering values for the spring and damper properties Load magnitude You can apply a Load in the joint variable This will be a Torque or a Force depending on whether the joint variable is a translational or a rotational degree of freedom Stress free length angle control This group of options concerns spring deflection calculation similar to the Length Angle control of a Prescribed joint variable See also Section 4 7 1 Spring properties Spring properties This group of options concerns the spring characteristics namely the relation between deflection and force See Section 4 7 1 Spring properties for details Damper force coefficient This group of options concerns the damper characteristics namely the relation between velocity and force See Section 4 7 2 Damper propertie
193. ctly NOTE The center of the applied rotations are always the origin of the Coordinate system in question The position controlled by the Position options and not at the origin of the selected reference CS 3 14 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 6 Attaching and detaching elements pcc Y Visualization The sizes displayed in the Position frame are visualized along with the reference CS for the orientation whenever the Origin Property is visible The visual appearance of this visualization is shown in the E o picture Y o The object to move red In this example a Triad o Position arrows pink Shows the various dimensions corresponding to the selected Coordinate Type as arrows extending from the reference CS for the position EJ Reference CS for the position Reference CS for the Orientation The reference CS for the Orientation is shown by the purple line from the object to move to the reference CS Q Orientation Reference direction The reference directions for the orientation are shown as purple lines and letters indicating the orientation of the reference superimposed on the position of the object to move o 3 6 Attaching and detaching elements Nearly all mechanism elements created in Fedem needs to be attached to a link or two The concept of attaching is to connect the joint constraints loads etc to the parts they affect When attaching two things happen
194. cts Loads Two types of loads can be applied to triads or links forces and torques Both types are applied as point force vectors on FE nodes These loads can be used to introduce motion into your mechanism During To simulation the magnitude of forces and torques can be constant or controlled by functions see Section 4 10 Functions When creating them it is possible to add a load directly to an existing triad or to an FE node OT o m A E EM co 4 8 1 Load symbols Force Torque The symbols for forces and torques are Y displayed in the Modeler as shown to the left 4 46 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 8 Loads EE 4 8 2 Load properties The magnitude and direction of a force torque vector can be edited in the Property Editor panel shown below Select the force or torque to show its properties Description Magnitude aGuiiiiu1r il Direction eo 100 0000 1 From Load Target Point eo 1 Link Gnd Link Gnd Reference Local ex Reference Local X e Reference Local X x 0 4564941 0 07296870 99 Wu Y Zz 0 0 Apply zZ 0 0 E 1 000000 Magnitude to change the load magnitude enter a constant value or select one from the list of functions in your model see Section 4 10 alle Mio lli Functions Load Target Point the point is given in either global or local cx coordinates You can also select a new target point u
195. culations for help Print out this help text false HistDataType Histogram data type 0 0 None 1 Signed abs max stress 2 Signed abs max strain HistXBins Histogram number of X bins 64 HistXMax Histogram max X value 100 HistXMin Histogram min X value 100 HistYBins Histogram number of Y bins 64 Fedem Release 5 0 User s Guide E Command line options E 7 Strain coat recovery options fedem_fpp Command line Description Default value option p HistYMax Histogram max Y value 100 HistYMin Histogram min Y value 100 licenseinfo Print out license information at startup false licensepath License file directory linkId Link base ID number 0 linkfile Name of link input file PVXGate Gate value for the Peak Valley extraction 10 MPa or microns depending on Hist DataType rdbfile Name of strain coat results database file rdbinc Increment number for the results data 1 base file resfile Name of result output file resStressFile Name of residual stress input file resStressSet Name of residual stress set samfile Name of SAM data file SNfile Name of SN curve definition file statm Start time 0 stotm Stop time 1 stressToMPaScale Stress convertion factor to MPa 1e 06 surcface Surface selection option 0 0 All element surfaces 1 Bottom shell surfaces only 2 Middle shell surfaces only 3 Top shell surfaces only terminal
196. d by the residual stress will not be accounted for in the simulation NOTE The imported residual stress state is also applied in the Strain Coat Recovery see Section 6 9 3 Import of residual stresses from external analyses but currently not in the Strain Gage recovery 6 6 4 Starting the analysis Once you have set up the stress recovery options and performed the H ial dynamics simulation you can start the stress recovery for the selected time steps by clicking the Recover Stress button on the Solvers toolbar or Solve menu You may also run the stress recovery only on one or a selection of links or on individual element groups see Section 6 2 4 Link and group wise solving 6 NOTE If element calculations fail during stress recovery analysis the recovery continues on the other elements All failed elements will appear grey in the contour plot after the animation is loaded 6 7 Mode shape recovery analysis 6 7 1 Mode shape options To animate or display detailed mechanism mode shapes you must first set up and perform the dynamics analysis and then the mode shape recovery analysis NOTE Rigid body mode shapes can be animated without a mode shape recovery analysis see Section 7 3 2 Animation properties for more information To set up the mode shape analysis click the Mode Shape Recovery Setup button on the Solvers toolbar or Solve menu The Setup dialog is displayed as shown below You can then select the modes yo
197. d in any coordinate system in the model These pull down menus allows the reference CS s to be selected The reference CS s can also be selected by picking in the Modeler or selected from the Objects Browser To do so you must first click the arrow button next to the pull down menu The guide bar tells you to select a reference CS Select a triad or a link when satisfied press Done Coordinate type This menu controls whether to display the translation in cartesian coordinates or cylindrical coordinates The cylindrical coordinates can use either X Y or Z as the rotational axis G Coordinate type This menu controls how to edit and display the orientation The Orientations input type options are gt Angles about the X Y and Z axis in degrees The parameterization used is the one called Euler ZYX which means a rotation about the Z axis of the reference CS first then the Y axis of the reference CS and finally the X axis of the reference CS This can also be understood as a rotation about the axes of the with rotated or local X axis first then local Y and finally local Z gt A point on the X axis and a point in the XY plane The X and Y direction is then computed from the given point and the translation of the object gt A point on the Z axis and a point in the XZ plane gt Avector in the X direction and a vector in the XY plane In this mode the X and the Y vectors from a 3x3 rotation matrix can be used dire
198. d the from point and if necessary edit it using the Interactive Odometer to specify a discrete point 5 When you are satisfied with the to point press Done to confirm it The move operation is animated in the Modeler window 3 5 2 Align CS and rotations p The two align commands can be used to align one or several objects to fie dc an existing coordinate system in your model The Align CS command will both translate and rotate the selected objects to match their coordinate systems with the selected one while the A ign rotations command only rotates the selected objects Performing an Align command To move an object or group of objects using one of the align commands complete the following steps 1 Click the correct Align button in the Mechanism Tools toolbar They are located under the Smart Move icon 2 Selectthe objects to move by picking them in the Modeler view Press Done to confirm the selection TIP Several objects can be selected by pressing and holding the Ctrl key while selecting objects To change the last selected object only release the Ctrl key and select until you hit the right object To remove several of the last selected objects from the selection release the Ctrl key and press the left mouse button on some empty space in the modeler until all the objects in question is deselected 3 Select the coordinate system to align to by picking an object that is defined in that coordinate system The selected coo
199. d the road conditions These parameters can be derived from experimental data obtained from tests The tire is rolled over a road at various loads orientations and motion conditions The Magic Formula tire model is mainly of an empirical nature and contains a set of mathematical formula which are partly based ona physical background The Magic Formula calculates the forces Fy Fy and moments M My M acting on the tire at pure and combined slip conditions using longitudinal and or lateral slip x a wheel camber y and the vertical force F as input quantities The model takes into account plysteer and conicity An extension has been provided that describes transient and oscillatory tire behavior for limited frequencies smaller than 8 Hz and wavelengths larger than the tire cirrumference History of the Magic Formula Through the initiative of Volvo Car Corp a cooperate effort was started in the mid eighties with the Delft University of Technology to develop a tire model that accurately describes the tire s ability to have horizontal forces generated between road and tire The first Magic Formula version was presented in 1987 3 The basic idea of using the sine and arcsine functions was described for mainly pure slip conditions Further prototype formula were proposed for combined slip conditions In the second version 4 presented in 1989 the formula for combined cornering conditions based on physical background were improved
200. data collected from the mechanism analysis see Chapter 6 Mechanism Analysis The options for postprocessing are graphing and animating You can perform these functions using the Model Manager Results list and the tools included on the Result menu Results are displayed in the Workspace area Model Manager Results list Objects Resuts The Model Manager Results list shown at right diem displays the list of user defined result view objects in 1 Front rotation your model In addition to the commands available SUA Huan in the Result menu see below many shortcut commands can be used to manage results in the g aE aT Results list The shortcut menu is accessed by New Curve right clicking in the Model Manager panel see figure ic New Graph to the right and displays commands relevant for the EA New Animation selected object 4 show Graph cuis Import b Each curve in the Model Manager Result list has an Export icon next to the curve name representing its legend Ebr Sort by Name The curve color and symbol can be changed in the z n n Delet Del Appearance tab See Section 7 2 8 Appearance Lipi s Result menu The Result menu shown at right Result selector contains commands for creating result New Graph views and managing the result files in New Curve your model Use of these commands is ES New Animation explained in the following sections Men xac Es Load Animation Ctrh A B End An
201. de 2 19 2 7 2 3D View controls vis eue co view hae E MUERE RE M aoe he 2 22 2 7 3 Zoom and Pan cesses wea i ELI TERR RR 2 23 2 7 4 General Appearance ccc cece cece cece cece nent nee e ee enee tenes 2 24 2 7 5 Item Appearance iss ileceni e bac eEE RO RUE ECKE A Sea OE OM eee 2 27 2 7 6 Element face visibility esses 2 28 2 7 7 Visualization of special finite elements 0 cece cece eee e eens 2 29 Opening and saving model files cece cece eee eee e es 2 30 2 8 1 Opening a files rreri r eroi s TEA A RILE whee TIETAN IA soe 2 30 2 8 2 Saving models orar eo te eR ae ETEA ERANA ERE Ere C 2 32 2 8 3 Starting a new MOdel cece eee eee e eene 2 33 Loading and unloading FE Data c ccc ee eee cence eens 2 33 2 9 1 FE Data Settings oie fa aana oa NS IP NU pIR ESSE ole RUE 2 33 2 9 2 Skipping FE Data when opening a model file 0 eee eee 2 34 Fedem Release 5 0 User s Guide 2 10 2 11 2 12 Chapter 3 3 1 32 3 3 3 4 2 9 3 Modeling with unloaded links cece cece eee cece nent eens 2 34 2 9 4 Postprocessing unloaded links ce cece eee e eee eect ene enee 2 35 Printing and exportingus duas usse ead NY SO EAR YR Ri Cap E 2 35 210 1 Printing vec e xEREHEEE E ux eer UI x wes adem t epe ren 2 35 2 10 2 EXPONO s Oe AM ORI MEME 2 35 Licensednformatlolkcseccevne a torso ees COH IBS e Ope SQ C hate 2 38 2 11 1 Available modules essnee
202. define the Start time and the Stop time of the dynamics simulation You can define the size of the Time increment to be used by the time integration algorithm In addition to a constant value you may also select a Function or a Time history input file from the pull down menu in order to obtain a varying time increment size see Section 4 10 Functions In that case the Minimum time increment is used as a lower bound on the step size Q You can enable disable the use of Iteration cut back when the dynamics simulation diverges and Dynamics Solver Setup Integration Tolerances Eigenmode Initial Equilibrium Output Simulation time 1 Start time foo e Stop time hoo oS 2 Time increment 0 01 Al Minimum time increment Don Iteration cut back Perform cut back on divergence Step size reduction factor Number of steps with reduced size Restart Perform restart Restart time adjust the Step size reduction factor defining the size of the new time step to use in the cut back and the Number of time steps with reduced Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis Es size before the normal step size is resumed If the cut back iterations also diverge another cut back is attempted by applying the Step size reduction factor again This procedure is then repeated until convergence is obtained or the Minimum time increment is reached In the latter case t
203. deling process Fedem provides some helpful modeling tools including a reference plane an interactive point locator point markers and movability constraints 3 3 1 Reference Plane The Reference Plane is the shaded area in the center of the Modeler window It serves both as a visual reference and as a representation of the ground You can move it around change its color and size or turn it off so that it is not visible in the Modeler window To disable enable or change the appearance of the reference plane see Section 2 7 4 General Appearance and Section 2 7 5 Item Appearance Changing the size To change the size of the Reference Plane select the Reference Plane in the Modeler window or Model Manager Objects list then edit its Height 3 4 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 3 Mechanism modeling tools 3 3 2 and Width fields in the Property Editor panel shown below Remember to press Enter after typing the values to apply the changes Pasition Orientation Reference CS Coordinate type Reference CS Coordinate type Global ikl Cartesian XYZ x Global zik EuleiZYX as X Y Z x x Y z Rot Deg RotY Deg RotZ Deg 0 0 0 0 foo 0 0 0 0 0 0 Size Height 1 0 Width 1 0 Moving The Reference plane is moved by editing the Position and Orientation fields in the Property Editor panel See Section 3 5 4 Origin property for a detailed description of these data fields
204. dem Release 5 0 User s Guide A 29 A Using the MF Tyre Model A 6 Steady State Magic Formula A 6 3 Transient Behavior Figure A 13 Stretched String Model for Transient Tire Behavior Tw E 9 5 elastic foundation path of contact points stretched string M VLA A 6 4 Transient Model Equations The present version using slip speeds instead of a and k allows starting from stand still First order lag of tire longitudinal and lateral deformations u and v are introduced through relaxation lengths sk and sa see Figures A 13 d Erud o V A 86 K SX o ry 0 V A 87 Q sy These differential equations are based on the assumption that the contact points near the leading edge remain in the adhesion with the road surface no sliding The relaxation lengths in this version not considered to decrease with increasing composite deformation slip are functions of the vertical load and camber angle represented in a similar way as the slip stiffnesses Kx Eq A 12 and Ky Eq A 23 Ok F Gr Pryadf i exp p ry3dfz Ro F z0 i Aok A 88 Oa Pryisin 2atan F O rF 0AF 5 i a PyyalY Rog Aoa A 89 The practical tire deformation slip quantities are defined as x sign V A 90 K tana a A 91 Oa A 30 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula ss Equations A 56 A 65 A 76 A 83 and A 84 are subs
205. dem Release 5 0 User s Guide A 25 A Using the MF Tyre Model A 6 Steady State Magic Formula es S xa Vay A 63 The weighting function follows as 7 cos C arctan B a E B a arctan B a A 64 xa cos C arctan B S5 EL Bu Sg arctan By Sp 1 Table A 12 Longitudinal Coefficients Combined Slip Name saben file tire Explanation rBxd RBX1 Slope factor for combined slip Fx reduction IBx2 RBX2 Variation of slope Fx reduction with kappa c1 RCX1 Shape factor for combined slip Fx reduction l Ex1 REX1 Curvature factor of combined Fx l Ex2 REX2 Curvature factor of combined Fx with load Hx RHX1 Shift factor for combined slip Fx reduction Formula Lateral Slip Combined Slip F Fo G x a K y F Syy A 65 with Gy a weighting function and SV the k induced side force can be written F D cos C arctan By Ks EAB UK arctan B k 1 4 P pu A 66 Ks K Sin A 67 with coefficients By rg cos aretanirg a 7r5 5 3 Aye A 68 Cyn 7 foyi A 69 D Se ee a A 70 ye cos Care tan UB yS Hye E By Sty arctan By Styx 1 A 26 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula i Ey ryt eyo A 71 Sry r Hy1 Tyr A 72 ST Dy sin ry sarctan ry cx A yy A 73 Di LF Fiyi rye r yy3Y cos arctan ry 40 A 74 The weighti
206. dem stressres 0 7 KB 5 15 2003 14 02 01 Ig Modes Recovery ES 2 Front 1 Enable Result B fedem modes Disable Result E fedem modes i E fedem modes a 2 Boom H 3 Bucket H 4_BellCrank H 5_BucketLink Delete Del Fedem Release 5 0 User s Guide 8 5 8 Managing Results 8 2 Result File Browser What you actually do when you disable a result file is to temporarily remove all the result information in the result file from memory and the results from that file will be unavailable for post processing curve plotting and animation As a result Fedem consumes less memory You may re enable the disabled results any time you wish The results from this file will then be available for post processing again NOTE Selecting a top level item in the file list will also automatically select any frs files located below that item in the list E NOTE Only results from the recovery processes are available for enabling disabling Deleting results Using the same approach as when Disabling and Enabling results you can also delete individual result files classes of results or results on selected links Just select the results you want to delete right click and select Delete from the menu File i Last modified l ED Reduction 5 b Modes Recovery i Boom 1 frs 251KB 5 16 2003 14 01 PI Boom 2 frs 251KB X 5 15 2003 14 01 PI Boom 3 frs 251KB X 5 15 200
207. des mi m2 Useonly these component modes ExclModes mi m2 Useall but these component modes The structural damping parameters entered in the Property Editor panel for a selected link see Part tab in Section 4 1 4 Link properties are by default applied to the whole stiffness and mass matrix of the link However it is possible to specify individual Rayleigh damping factors for each of the component modes through the following description field commands Alphal ci c2 Mass proportional damping factors for the component modes Alpha2 ci c2 Stiffness proportional damping factors for the component modes Thus lt c1 gt is the damping factor applied to the first component mode used c2 is the factor for the second mode etc If you specify fewer such individual damping factors than the number of component modes being used the last value entered is used for all the remaining modes Springs Spring stiffness for both axial and joint springs can be adjusted using scale functions Different adjustment for positive and negative deflection of a spring is often desirable when adjusting the stiffness of for instance hydraulic cylinders To achieve this use the description field commands PosStiffScaleEngine id NegStiffScaleEngine id The id is the function s base ID These commands set the scale function only for the respective deflection state If used they will over
208. developed by TNO through the STI interface For more information on the properties of these tire formulation please refer to the Appendix A Using the MF Tyre Model and Appendix B Using the SWIFT Tyre Model Fedem also interfaces the FTIRE tire model through the CTI interface defined by Cosin Consulting Details on FTIRE is available on www ftire com 4 9 1 Tire To create a tire press the tire icon and select a pou ie Revolute Joint that acts as the bearing between d the wheel carrier link and the spindle link The master triad of the joint must be attached to the j wheel carrier link the slave triad must be f A attached to the spindle The forces and torques from the tire will be applied to the slave triad of this joint 4 48 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 9 Tires and Roads NENNEN To complete the tire you have to edit some of the tire properties The tire property panel is shown below Tire file d FedemModels std_1 tof E l Browse Road None M J Tire model MF TYRE s Z offset 0 1000000 Tire file Select a tire data file that describes the properties of the tire This can be done by pressing the browse button and select a tire property file tpf or tir or select a file reference that refers to a tire file Please contact Fedem Technology or your tire supplier to get tire property files for your particular tires gt Road You also have to s
209. ding forces acting on the road due to the vibrations of the tire relative to the wheel rim Braking and traction torques are considered as acting on the rotating disc Figure A 2 Input and Output Variables of the Magic Formula Tire Model Input Magic Output Fy lt s Zg lt X N A4 Axis Systems and Definitions A 4 1 W Axis System MF Tyre conforms to the TYDEX STI conventions described in the TYDEX Format 1 and the Standard Tire Interface 2 Two TYDEX coordinate systems with ISO orientation are particularly important the C and W axis systems as detailed in Figure A 3 Fedem Release 5 0 User s Guide A 5 A Using the MF Tyre Model A 4 Axis Systems and Definitions A 6 A 4 2 Figure A 3 TYDEX C and W Axis Systems Used in MF Tyre According to TYDEX The C axis system is fixed to the wheel carrier with the longitudinal X axis parallel to the road and in the wheel plane x z plane The origin O of the C axis system is the wheel center The origin of the W axis system is the road contact point or point of intersection C defined by the intersection of the wheel plane the plane through the wheel spindle and the road tangent plane The orientation of the W axis system agrees to ISO The forces and torques calculated by MF MCTyre which depend on the vertical wheel load F along the z axis and the slip quantities are projected in the W axis system
210. directory limInitEquilstep Initial equilibrium step size limit 1 lineSearch Use line search in the nonlinear iterations false maxInc Maximum time increment 0 05 maxSeqNoUpdate Max number of sequential iterations with 100 out system matrix update maxit Maximum number of iterations 15 minInc Minimum time increment 0 001 minit Minimum number of iterations 1 modesfile Name of primary modes database file ev_p frs monitorIter Number of iterations to monitor before 2 maxit Fedem Release 5 0 User s Guide E Command line options E 3 Dynamics solver options fedem_solver Command line Description Default value option P monitorWorst Number of DOFs to monitor on poor con 6 vergence noStiffDamp Turn off rigid body filtering of stiff false Filtering ness proportional damping nosolveropt Switch off equation system reordering false numEigModes Number of eigenmodes to calculate 0 num damp energy Number of steps without calculation of 1 Skip energy from stiffness proportional damp ing numit Fixed number of iterations 0 nupdat Number of iterations with system matrix 0 update printinc Time between each print to result output 0 file quasiStatic Do a quasi static simulation to this time 0 rdbinc Increment number for the results data T base files resfile Name of result output file fedem_solver res restartfile Respo
211. displays a reference picture to easier remember the meaning of the different parameters Q Preview This tab has options to control preview of the function shape see Section 4 10 3 Preview 4 10 3 Preview To get an impression of the function shape you paameterHelp Preview may preview it as a curve in a graph Specify n Bo p the argument Domain and Increment in the x Increment IV Auto Jon preview tab of the Property Editor then push the Show button to plot A preview graph HEC containing the preview curve is then created and displayed The displayed curve is updated automatically when changing any of the function properties Most functions have the option to set the preview increment automatically This is enabled by default but can be disabled by toggling the Auto toggle The created graph and curve is automatically added to the Model Manager Results list and may be handled like any regular graph and curve Refer to Section 7 1 Postprocessing environment and Section 7 2 Graphs 4 52 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions es TIP The actual values of a function can also be plotted directly in a Graph when you have run a simulation or during a simulation To enable such plotting you must first specify the Additional Solver Option allEngineVars for the Dynamics Solver see Section 6 2 Additional solver options before starting the simulation such that the f
212. domain This can be used to simulate contact in pipes etc NOTE The Use radial stiffness toggle does not affect the dampers if any that are assigned to the joint variables They are still applied in the local Cartesian coordinate system It is therefore advisable to apply the same damping characteristics to the x and y variables when using radial stiffness to ensure a proper damping behavior in the cam joint Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 5 Joint pair constraints Cam with spherical or cylindrical follower Quite often the follower in a cam joint has some sort of spherical or cylindrical shape This is not fully supported by Fedem but this section describes how you can do it The radius of the sphere or cylinder must be entered as an nitial stress free length for the spring in the X translation DOF see Section 4 7 1 Spring properties Anormal contact stiffness function can then be used The Thickness of the cam must also be set to a value greater than the roller radius in this case This will work as expected as long as the follower never is supposed to be in contact with the cam curve at more than one location simultaneously This means that the follower can not pass the inside of a v shaped cam curve or curve segments that have a radius equal to or less than the roller radius By trying to do so the numerical simulation will normally fail to converge when two simultaneous contact locations would b
213. dric joint in a screw like connection r Output Ratio 0 0 by defining a ratio of translational to rotational motion called the screw ratio This ratio determines how fast the slave rotates as it translates along the joint To constrain the translational and rotational DOFs of a cylindric joint enable the Screw Connection option in the Property Editor panel and assign a value to the Screw Ratio See the Fedem R5 0 Theory Guide Section 6 4 3 Screw joint for more information about the screw ratio TIP You can refine the slider path by adding master triads in the same way as for prismatic joints see Prismatic joint above TIP A zero screw ratio makes the cylindric joint equivalent to a prismatic joint 4 32 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints Cam joint A cam joint has six unconstrained DOFs that allow the slave triad called fe the follower to move over a curved surface called the cam surface The cam surface is defined by a curve consisting of three point circular arcs Each arc is defined by the location of three master triads also called cam triads A cam joint must consist of one slave follower triad and at least three master cam triads See also the Fedem R5 0 Theory Guide Section 6 3 3 Cam joint It is recommended to use at least an arc segment per quarter of a circle to make the solution more stable That means that you will need at least 8 master triads fo
214. e vou can enable disable both the Geometric Stiffness Contribution and the Centripetal Moment Correction during the non linear iterations The geometric stiffness option accounts for stress stiffening in links and axial springs and dampers It may therefore improve the convergence of the nonlinear iterations if the mechanism contains links with large membrane forces or axial springs and dampers with large axial forces This is because the forces alters the bending or rotational stiffness of these elements A tensile membrane axial force will effectively increase the bending rotational stiffness anda compressive force will reduce the bending rational stiffness For information on the computation of the geometric stiffness on links see the Fedem R5 0 Theory Guide Section 4 4 Superelement tangent stiffness The centripetal moment correction option enables an improved representation of the inertia forces on links that have only a few Triads but experience high speed rotations see the Fedem R5 0 Theory Guide Section 3 3 Inertia forces and high speed rotation for 6 details Q You can specify the default algorithm for calculation of the co rotated link coordinate systems during the simulation The selections available in this pull down menu correspond to those of the similar pull down menu in the Advanced tab of the Link property panel see Section 4 1 Link properties The setting here applies to all links in the model wher
215. e STRUCTURAL C BXO Cbxo See Equation B 10 In plane transla tion belt frequency longitudinal relax ation length C RX Cy See Equation B 30 tuned value for optimal performance Longitudinal relaxation length C_BTO Cbqo see Equation B 11 Belt wind up rota tion frequency longitudinal relaxation length C BY Cby See Equation B 15 Out of plane translation belt frequency lateral relaxation length C RY Cry See Equation B 31 Out of plane translation belt frequency lateral relaxation length B Using the SWIFT Tyre Model B 4 Tire Model Parameters Table B 8 Definition of Parameters in Tire Property File Continued User Notes Tire parameter manus js Tire characteristic if applicable C BGAM Cbg See Equation B 16 Belt Camber yaw rotation frequency lateral relaxation length C RP Cry See Equation B 32 tuned value for optimal performance Aligning moment at short wavelength K BX kpx See Equation B 12 damping for in plane translation belt frequency K RX ks See Equation B 30 tuned value for optimal performance K BT Kbq See Equation B 14 damping for wind up belt frequency K_BY kpy See Equation B 15 damping for lateral belt frequency K RY kry See Equation B 31 K_BGAM kbg See Equation B 16 Belt Camber yaw rotation frequency lateral relaxation length K RP krp See Equation B 32 tuned value for optimal performance Q_BV
216. e Pa Normalized longitudinal residual deflec Ro tion D Normalized lateral residual deflection Ro Pry Yaw residual deflection rad W Wheel rotational speed rad s Q Normalized wheel rotation speed W Op Nominal wheel rotation speed rad s Misi Longitudinal contact point velocity m s Vo Nominal wheel speed m s Vx Wheel speed m s Table B 6 Stiffness and Damping Symbol Description Units seas Cpx Translation belt stiffness N m Normalized in plane translation belt Cio bx stiffness 2 Normalized nominal in plane transla Cio bx0 tion belt stiffness Cby Lateral belt stiffness N m 2 Normalized out of plane translation Cio by belt stiffness Chy Out of plane rotation belt stiffness N m l Normalized out of plane rotation belt Cro by stiffness Cpo Wind up belt stiffness N m 7 Normalized in plane rotation belt stiff Cio 5g ness Fedem Release 5 0 User s Guide B 7 B Using the SWIFT Tyre Model B 3 Force Evaluation B 3 Force Evaluation B 3 1 Rigid Ring Model The tire belt is modelled as a rigid body with mass and moments of inertia that is suspended with spring damper systems to the rim The stiffness of the springs is calculated from the frequencies of the so called rigid body modes The gravitational force is along the global Z axis and is defined in accordance with Equation B 8 JU x Co Mo B 8 B 3 2 In Plane Characteristics Figure B 1 shows a side vie
217. e expected If the cam curve to be modeled has this kind of features you will need to model the different parts of the contact curve as separate cam joints instead and re use the same triad as follower in all those cam joints You will also have to set them up with the same contact spring characteristics and Initial Stress free length CAUTION When using a radius on the follower even small discontinuities of the cam tangent between curve segments might result in a v shaped curve The v s can cause numerical problems if the follower is on the inside of it 45 Joint pair constraints Joint pairs available in Fedem include both Gears and Rack and Pinion 4 5 1 Gears a A gear is a rotational constraint between two revolute joints The gear E 5 constrains the two joints to rotate at a given transmission ratio Gear symbol i li The gear symbol shown at right is ATN ge displayed in the Modeler window asa line 4 P between two revolute joints EL en Fedem Release 5 0 User s Guide 4 37 4 Mechanism Elements 4 6 Frictions Transmission ratio You can specify the gear transmission ratio Sasi dimensionless rate in the Property Editor p Transmission Ratio panel shown at right For information dE about the gear transmission ratio see the Fedem R5 0 Theory Guide Section 6 4 1 Gear joint 4 5 2 Raclcand Pinion A Rack and Pinion is a constraint between a prismatic and a revolute im Ei joi
218. e file contents Detailed information on the full contents of the data section is listed below Data output Time Description of output Time Strain XX in rosette coordinate system Strain YY in rosette coordinate system Shear strain XY in rosette coordinate system First principle strain Second principle strain Ymax Max shear strain Angle from rosette X axis to direction of principle strain Angle from rosette X axis to direction of max shear Stress XX in rosette coordinate system Stress YY in rosette coordinate system Shear stress XY in rosette coordinate system von Mises von Mises stress 961 First principle stress 905 Second principle stress Fedem Release 5 0 User s Guide 6 37 6 Mechanism Analysis 6 8 Strain rosette analysis SS LID LI Data output Description of output Tmax Max shear stress Egage1 Strain in leg1 Egage2 Strain in leg2 Egage3 Strain in leg3 All angles are output in degrees to the ASCII file File buffering and flush frequency The output to the frs file may be controlled using the additional option flushinc which works in the same manner as with the Dynamics Solver see Section 6 5 2 Result output control However the default value is here 1 0 i e the file is flushed to disk when the internal fixed size file buffer is filled Note that this option only affects the frs f
219. e or more of the commands Freex FreeY FreeZ FreeRX FreeRY FreeRZ in the description field of the selected Rigid Joint The rotational parameterization is rotation axis components All DOFs are referred to master triad coordinate system F 1 4 Axial Joint An Axial Joint is obtained from the Free Joint when the command Axial is entered in the description field of the selected Free Joint This is a single DOF joint that works like an Axial Spring and or Damper except that the length between the two triads here is used as a joint DOF The Tx tab of the joint property panel see Section 4 4 2 Joint properties is used to control the behavior of the length DOF All the other DOF tabs of the property panel are not used when Axialis specified The advantage of using an Axial Joint opposed to a combined Axial Spring and Damper is that you now are able to prescribe the length between the two triads directly without the need for stiff springs and associated damping which might render the model numerically unstable It also reduces the total number of DOFs in the mechanism compared with an Axial Spring Damper reduced by 5 for each Axial Joint More details on the formulation of the Axial Joint may be found in the Fedem R5 0 Theory Guide Section 6 2 7 Axial Joint F1 5 FreeJoint An alternative Free Joint formulation is now available through the specification of the following description field command GlobalSpring Fedem
220. e the normalized vertical load increment df is defined F F df z z0 z0 A 14 with the possibly adapted nominal load using the user scaling factor zo Fig Fr z0 A 15 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre ei Tire Model Parameters In the subsequent sections formulae are given with non dimensional parameters aj with the following values and connections Table A 5 Tire Model Parameters Parameter Definition a p Force at pure slip q Moment at pure slip Force at combined slip Moment at combined slip Stiffness factor Shape factor Peak value Curvature factor Slip stiffness BCD Horizontal shift lt II Aim OLN vay Vertical shift Moment at combined slip Transient tire behavior m Along the longitudinal axis Along the lateral axis About the vertical axis A 5 4 User Scaling Factors NIX X N For the user convenience a set of scaling factors is available to examine the influence of changing a number of important overall parameters The Fedem Release 5 0 User s Guide A 15 A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre es default value of these factors is one The following factors have been defined Ta
221. e 7 3 7 2 1 Creating graphs and curves issssssssseseees e 7 4 7 2 2 Moving curves to a new graph cece cece eee eect e ene e ee eees 7 6 Fedem Release 5 0 User s Guide xi 7 3 7 4 Chapter 8 xii 8 1 8 2 7 2 3 Showing a graph cece cece cece cece een hehe eae 7 6 7 24 Graph properties od veio cag Bes pee hehe wedded eee Ha 7 6 7 2 5 Curve properties Te ecce ec eer RR e exc e o t ice ute Ce AR rn 7 7 7 2 6 Fourieranalysis cere ee een I EEAPUNUPETR US UU 7 13 7 2 7 Seale and Shift narioa e ee t Eee RR es eR a coeds 7 14 7 2 8 Appearatice heise aA RR Rr ERIS ES IRAE 7 15 7 2 9 Curve Statistics ceto enoxotvee ey E ev ER e I RARE e dd ids 7 15 7 2 10 Fatigue calculation from standard S N curves 0cce cece eee eee 7 16 4241 View control eider rere tote roov ped ve edes 7 17 7 2 12 Export of Curve Data 0 cece cece cece nee eee 7 18 7 2 3 Importing Curves and Graphs cece cece e cence ence eee en eee 7 20 7 2 14 Exporting to picture files sss 7 20 7 2 15 Printing graphs so v EE RAE ELE FECE eae ane cede 7 21 PATIL ONS he aes ccd hdres tori PEE 7 21 7 3 1 Managing animations 0 cece ccc cece ee nemen 7 22 7 3 2 Animation properties sssseeseeseesese cence nen een e ee eeaee 7 23 7 3 3 Available animation results 0 0 cece cece ence eee e cnet eenees 7 29 7 3 4 Performance of animation loading sleeeeeeeeeeeeeses
222. e CAD system and the other one in Fedem itself In the CAD system the Fedem menu provides the commands while in Fedem itself there are two commands i located in Mechanism Creation toolbar See Section 2 5 2 Menus and toolbars The Fedem menu is where the different commands to create open update and keep track of the Fedem simulation models associated with a FedemSolid assembly model can be found This menu is only visible when the active document is an assembly Fedem Release 5 0 User s Guide 2 39 2 Learning the Basics 2 12 Using the CAD integration The following topics cover how the interoperation works Model association How CAD assembly configurations relate to the Fedem Analysis models How parts and subassemblies translate to Fedem links gt Process communication Commands in CAD system the Fedem menu New Fedem Model Open Fedem Model Update Fedem Model List connected Fedem Models Commands in Fedem Connect to CAD system Open associated CAD assembly 2 12 2 Model association Each configuration can have an independent Fedem model associated with it The Fedem commands New Fedem Model Update Fedem Model and Open Fedem Model are working with respect to the current configuration and the Fedem model file if any which name is stored within the configuration The Fedem models are stored in a directory called assemblyname FEDEMin the same directory as the FedemSolid
223. e Del Export graph statistics When you select a directory to export to the files will be given names automatically The file name will be on the form G OwnerGraphlD C CurvelD CurveDescription Format 7 18 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs i TIP Curves that plot result data from the Dynamics Solver may also be exported automatically when the solver has finished see Output tab in Section 6 5 1 NOTE The exported data is equal to the results from the settings in the Fourier Analysis tab and the Scale and Shift tab If you want to export unprocessed data go to these tabs and set all the values back to default see Section 7 2 6 Fourier analysis and Section 7 2 7 Scale and Shift CAUTION When exporting to nCode DAC or MTS RPCIII Ax needs to be constant across the entire data set Using either Physical Time with constant time step size or Time Step Number will satisfy this requirement Graph export Objects Result n ge ESl nimations When exporting one or more pelaraphs T ia 2 1 Front rotation graphs each file exported will fH angle 2 velocity ift rotation angle velocity im length contain several curves The file format is either Multi Column ASCII or MTS RPCIII time history file p B Result selector i 13 Ta New Curve 5 Eigen El New Graph eiM El New Animation h 3 v FQ Show Graph ctrleG Select t
224. e Fedem UI To create a complete RDB structure with input files for all the Fedem solver processes except FE Fatigue and Duty Cycle click the Prepare for batch execution button on the Solvers toolbar or in the Solve menu The RDB structure required for a certain solver process can also be created by issuing the following command from a terminal window fedem f mname prepareBatch sname where the meaning of mname and sname is as explained above in Section 6 14 Batch solving trough the User Interface except that the keyword dutycycleis not available here Thus the effect of this command is exactly the same as with the solve option except that the solver processes themselves are not executed Specifying sname all 6 50 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 15 How to read error messages from the solvers 6 15 with this command is equivalent to using the Prepare for batch execution button in the Ul When the command have exited you have the necessary RDB directory structure which can be transferred to the remote computer for batch execution How to read error messages from the solvers When a solver process fails to complete a simulation task or any abnormality occur during the simulation messages explaining the problem are written to the Output List during the process execution These messages are prefixed either by Error Warning or Note signifying something about their severity Th
225. e at a later stage 8 3 2 Response directory structure The response_ directory is the entry point to result files from dynamics simulation and recovery operations Option files for the dynamics solver are stored directly in the response_ directory These files can be used to run the solver in batch mode Fedem Release 5 0 User s Guide 8 9 8 Managing Results 8 3 RDB directory structure CAUTION These files are auto generated from the main Fedem application Manually changing the contents of these files and running the solver from the command line creates results that are inconsistent with the definitions in the model file All results files in the response_ structure are stored in the same format but are placed in different directories making separate result types easily distinguishable The recovery modules will store their results in a linkwise manner in subdirectories under their main result directory named ID _ linkname _ where IDis the link identification number All option files are also stored in these subdirectories The following is a list of the result directories and a description of their contents timehist_prim_ The primary time history result files are named th p frsand contain primary response results from the dynamics solver timehist sec ff 4 The secondary time history result files are named th s frsand contain all secondary response results from the dynamics solver
226. e command to create a triad along the cylinder axis start selecting the tree nodes that define the circle If you pick a triad that triad will become selected and will be attached through the surface connector If you pick an FE node the node will be used as the first of three nodes that defines the cylinder circle If you pick something else the snap point will be used as the position for a new triad If you get it wrong try again until you have selected what you want then accept by pressing Done 3 Then select the rest of the tree points defining the cylinder circle accepting each node by pressing Done A cylinder circle visualization will show the resulting cylinder as you select the last node 4 When the cylinder circle is defined you can now or after any of the following steps press Done to complete the command using the definition of the cylinder that is shown The optionally new triad will then be created in the center of the circle if you did not define a position for it in the start of the command 5 The next steps is to select the start and end of the cylinder Do this by selecting an FE node for the start and one for the end Accept each of them by pressing Done Fedem Release 5 0 User s Guide 3 19 3 Mechanism Modeling 3 6 Attaching and detaching elements 6 Finally the position of the optionally new triad along the cylinder axis can be selected Press Done to accept When the command is completed Fedem s
227. e encountered Nevertheless it is good practice to go over the FE model once again and check for bad elements if you get warnings on negative pivots WARNING Using a reduced link with many negative pivots in its stiffness matrix may lead to instabilities in the subsequent Dynamics simulation and should be avoided Only a few negative pivots in a large link is normally not a problem however That has at most only local influence on the results in the vicinity of the elements with the negative pivots 6 3 5 Eigenvalue analysis of the reduced links To assess the dynamic properties of the reduced link matrices you can perform an eigenvalue analysis of the reduced system i e K o M 0 where K and M denote the reduced stiffness and mass matrices from equation 3 15 in the Fedem R5 0 Theory Guide Since the reduced system does not include any constrained DOFs the first six eigenvalues should always be zero The remaining eigenvalues can then be used to assess the dynamic properties of the reduced link The n lowest eigenfrequencies i e the quantities for each reduced link can be written to the corresponding res file by specifying nevred nin the Link Reducer field in the Additional Solver Options window see Section 6 2 3 Additional solver options The 1 DOFs that should be constrained are retained during the link reduction and are constrained only during the system analysis by the dynamics solver 6 14 Fedem Release 5
228. e in a Combined sine function is specified less than or equal to zero that is interpreted as infinity 4 60 Fedem Release 5 0 User s Guide 4 10 Functions 4 Mechanism Elements Delayed combined sine C A sin 2n fvo 0 A sin 2n f5v9 05 v vg Avy C t A sin 2n fjv 0 A sin 2n f jv 0 v vg ftv H C offset mean value Displace A A amplitude ment fi f frequency Hz Fg q1 d phase shift fraction of period t _1 i p vg delay Start v Periodic square pulse C A a ayes fv 9 0 ne0 1 2 2n 1 n C A v 0xs 2fo fo ftv EET ar Ampl H C offset displacement AT J A amplitude Displace fo frequency inHz when v is time ment L 0 phase shift L L L L L w Phase Period 5 shift 4 61 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions Linear derivative function f k 0 l iw i l V Y Ta RH Y4 V E SSA 7 s 1 l va l pagos oJ l V4 V3 fo Ae Ld pug a l ANU fos ys H I TE g og up E 1 1 Yi V3V3V4 Vs Vg Vj Vg Vio V9 0Sv w s V SV lt v V4S V lt V3 s V3 SV lt V4 V4SvV vs gt Vs SV lt V6 s Vg SV V4 s V7 V lt Vg s Vg V VO s Yo Sv lt Vio fv red 0 To add many numbers to a linear derivative function copy and paste is feasible Copy
229. e joint s triads are labeled master while one triad is labeled slave with the constrained DOFs of the slave triad following the movement of the master s See the Fedem R5 0 Theory Guide Chapter 6 Modeling of Joints To attach a joint to links the joint s master triad is attached to an FE node on one link and the slave triad to an FE node on another link This means that when the mechanism moves the FE node and link on the slave side of the joint follows the motion of those on the master side FE nodes and links can therefore also be referred to as masters and slaves See Section 3 6 Attaching and detaching elements and Section 3 6 1 Attaching using Attach about how to attach joints TiP To determine which triad is the master and which is the slave select one of the links or the joint to examine the Topology List of master and slave triads connected to the link joint You can then select click and hold down the mouse button the master slave triad to highlight it in the Modeler window 4 1 Joint variables The joint variables are the accessible or controllable degrees of freedom for each joint As an example the Revolute Joint normally has one accessible degree of freedom namely the rotation about one axis The other degrees of freedom are fixed For most joints the DOFs that are not accessible are fixed but for Prismatic and Cylindrical joints that is not the 4 20 Fedem Release 5 0 User s Guide 4 Mechanism Ele
230. e link coordinate system is in the global origin Centre of Gravity The Generic Part s centre of gravity can be positioned independently from the link coordinate system Q simplified visualization The lines extending from the centre of gravity to each of the triads attached provides a coarse visualization of the Generic Part 4 1 1 Creating links by file import Links can be created by importing FE model files or by importing CAD geometry as VRML files The available file formats are listed in Section 2 3 Storing models and results Importing FE models will create a link and set it up as an FE Part while importing a VRML file will create a link and set it up as a Generic Part To do so complete the following steps Fedem Release 5 0 User s Guide 4 3 4 Mechanism Elements 4 1 Links 1 Click the Load Link button on the Mechanism Creation toolbar or ly select from the File menu The dialog shown below then pops up Load link T boom3 02 bat T boom 4 bdf e carriage bdf T boom3 02b bdf T boom_sg bdf Wi dg bdf FB boom3 03 bdf T BoomCylBoomRBolt bdt T dipperl bdf T boom3 03new bdt TA bucket1 bdf TA dipper2 00 bdf T boom3 03new2 bdf T bucket2 bdf T dipper2 bdf T boom3 00 bdf RP boom3 03new3 bdf RP bucketleverl bdf BW DipperCylBoomR Bolt TA boom3 01 bdf TA boom3 bdf P bucketlink1 bdf BI do bdf File name PY File type Nastran Bulk Data bdf nas i v Cancel Unit conversion n
231. e step unless we force a physical flush Instead of relying on the fixed size internal buffer you may also instruct the solver to do a physical flush at fixed time intervals flushinc gt 0 0 An external buffer is then allocated for each result file which is big enough to just hold the number of time steps corresponding to the given flush interval This can be used to reduce the number of file IO operations to a minimum and may speed up the overall solution time if you have a slow disk or data network if using a remote device Moreover if the model is so big that a single time step does not fit in the internal buffer it will write data physically to the file in several steps during a time step and you may risk synchronization problems in a simultaneous simulation animation plotting Specifying a flushinc greater than or equal the simulation time step size will prevent this By specifying a flush interval less than zero you let the operating system decide when it wants to physically write data to file When running the solver batch or through the user interface with no graphs or animations loaded this is normally sufficient unless you have a slow disk drive then flushinc 0 0 may work better This is also equivalent to the behavior of the R3 0 solver or earlier versions TIP For small models i e few system degrees of freedom that run over a long time span using a huge number of time steps the default value flushinc 2 0 0
232. e the corresponding setting on the link level is Model default Fedem Release 5 0 User s Guide 6 21 6 Mechanism Analysis 6 5 Dynamics analysis 6 22 Tolerances tab Convergence criteria for the dynamics analysis are defined by enabling one or more convergence tolerances 1 This allows you to Dynamics Solver Setup DER enable disable and set convergence tolerances for the Displacement iteration Time Integration Eigenmode Initial Equilibrium Output Displacement iteration correction 0 Scaled vector norm 1 000000000000e 006 corrections Max disp 0001 Max rotation 3 2 You can define a convergence criterion on Velocity iteration Mes odis corre ct r on 2 Scaled vector norm 1 000000000000e 006 You can defi ne va rio us Unbalanced forces residual tolerances for Unbalanced e onm gantor nom jax force 0 forces Max torque 1 0 vou can define convergence Iteration energy change tolerances for iteration 4 Wier averse ooooo0000000e 006 energy changes Max DOF energy 0 0001 5 All available convergence A Se oree e E ELSE O Set of tests where ONE must be satisfied tests can be ignored or Ii loncred teats defined into one of two sets of tests In set A all tests must be satisfied for convergence ok Apply Cancel to be satisfied In set O only one of the tests must be satisfied in addition to all the tests in set A for convergence to be satisfied The various norms used in the
233. e the graph window This command is turned on whenever the X key is pressed while viewing a graph gt Toadjustthe graph axes so that the entire curves fit into the graph view click the Zoom All button or press F5 gt You can use the Zoom Window With Autoscale command to zoom in on an 7 2 12 Export of Curve Data Curve and Graph objects in Fedem can be exported to files for further processing in external software We distinguish between exporting graphs and exporting curves Curve export When exporting one or more curves each curve is written to a separate file The file format can be either Single Column ASCII nCode DAC or MTS RPCIII time history file To export curves select the curve Or Objects Results curves you want to export in the oe e raphs Model Manager Results List 5 1 Front rotation right click and select Export gt db 1 1 1 2 Lift rotation Export Curves A file dialog will pop imac up If you have selected only one 5 velocity 3 Boom length curve you can select location and B file name of the exported curve If you have selected several curves T ER you must select a directory to export RE show Graph cuc to If you select a graph all its curves IB Load import 5 will be exported Eo e o o Sort by ID T Result selector 3l Ta New Curve n zal New Graph New Animation u 9 amp 5S Export Curves Export Graphs Sort by Name Delet
234. e variables false allFrictionVars Output all friction variables false allGenDOFVars Output all generalized DOF variables false allHDVars Output all hydrodynamics variables false allJointVars Output all joint variables false allLengthVars Output all length variables false allLoadVars Output all external load variables false allRestartVars Output all variables needed for restart true allSecondaryVars Output all secondary variables true allSpringVars Output all spring variables false allstiffVars Output all spring stiffnesses false allSupelVars Output all superelement variables false allSystemVars Output all system variables false allTireVars Output all tire variables false allTriadVars Output all triad variables false allVelVars Output all velocity variables false alphaNewmark Numerical damping coefficient 0 1 autoTimeStep Time stepping procedure 0 0 Fixed time step size 1 Automatically computed time step size centripForceCorr Use centripetal force correction false Fedem Release 5 0 User s Guide E Command line options E 3 Dynamics solver options fedem solver Command line Fedem Release 5 0 User option Description Default value consolemsg Output error messages to console false ctrlAccuracy Accuracy parameter for control iterations 0 5 ctrlTolAbs Ab
235. e vibrations and n 1 for damped vibrations Available animation results The results available for animation depend on the solvers that have been run and their settings For an indication of which results that could be available use the Result File Browser see Section 8 2 Result File Browser TIP The heading of the frs files Fedem Result File is readable and could give valuable information in some cases If an animation is loaded without the contour results in question being present the legend text will display a question mark for the max and min values and no contour colors will appear Most of the results that can be utilized in a contour animation are produced during stress recovery All Element Node and Node results selected in the Result Class pull down are currently produced during stress recovery All Element results however are produced either directly s Guide 7 29 7 Postprocessing Results aes 7 30 7 3 Animations by the Strain Coat Recovery Summary by FE Fatigue or by Duty Cycle analysis Element results produced during the Strain Coat Recovery Summary VVVVVVVVVVVYVVYY Max principal stress Max principal strain Max shear stress Max shear strain Max von Mises stress Max von Mises strain Maximum stress range Maximum strain range Mean biaxiality Biaxiality standard deviation Most popular angle Angle Spread Damage Life repeats Life equnits Element results that can be produ
236. e2 mname is the Fedem model file fmm in which the curves to be exported are defined and cname is the name of the output file where the curve data is exported The module also have some other options to facilitate the export process see Appendix E 8 Curve export options fedem graphexp for a complete list of all options for this module 6 14 Batch execution of solver processes If you need to run several events for a given model e g when preparing for a Duty Cycle analysis etc it is normally most efficient to edit the model file directly in an editor or by means of scripting and then run the solver processes in batch mode from a terminal window or command line prompt To facilitate such batch executions a set of command line options is provided that runs Fedem in a non graphics and non interactive mode see Appendix E 1 Fedem UI Options fedem for the complete list of command line options for the Fedem UI 6 14 1 Batch solving trough the User Interface Start the Fedem UI from the command line prompt with the following command fedem f mname solve sname where mname is the Fedem model file and sname is one of the keywords reducer dynamics stress modes straingage Fedem Release 5 0 User s Guide 6 49 6 Mechanism Analysis 6 14 Batch execution of solver processes NENNEN straincoat dutycycleorall This will read the specified model file and immediately launch the specified solver process e
237. echanism Model mm format 2 3 Fedem Technology Link t 1 format 2 3 link files 2 3 MSC Nastran Bulk Data File bdf or nas format 2 3 primary time history result files 8 10 results from eigenvalue recovery 8 10 results from stress recovery 8 10 solid view 2 22 solution processes stopping 6 48 solvers command line options E 1 running in batch mode 8 9 setting up parameters 6 5 Solvers toolbar about 6 5 accessing commands 6 5 speed slider 7 33 spring inter connectivity 4 25 springs assigning values 4 21 changing stress free length during simulation 4 40 properties 4 40 simulation results 2 3 strain coat analysis 6 40 options 6 41 recovery 6 43 strain coat elements 6 40 strain rosette analysis 1 7 6 35 options 6 35 result files 6 36 strain rosette definition 6 38 stress analysis 1 2 improving performance 6 31 specifying parameters 6 4 6 31 Stress concentration factor 4 17 stress recovery analysis 6 4 starting 6 33 superelements 1 4 6 2 Standard tire interface STI SWIFT Tyre defined A 35 about B 2 static equilibrium analysis contact model B 19 about 6 2 example road property file B 34 setting up 6 3 Status bar 2 7 STI standard tire interface defined A 35 example tire property file B 28 force evaluation B 8 notation for B 3 parameters B 22 Fedem Release 5 0 User s Guide Index l 11 I 12 Index road input B 14 switching from simp
238. ecovery analysis are output in single precision 32 bit real The output precision may if so wanted be set to double precision 64 bit real by using the double solver option 6 6 3 Import of residual stresses from external analyses Sometimes one or more parts in a model may be subjected to stresses from molding or other temperature processes that have been computed in other simulation packages These stresses may then be regarded as a residual stress state on which the stresses from the dynamics simulation in Fedem are superimposed You may specify an external results file with such residual stresses for each link in the Advanced tab of the Property Editor panel see Section 4 1 4 Link properties 6 32 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 7 Mode shape recovery analysis The stress state from the external results file is imported into the stress recovery module and added to the computed stresses from the dynamics simulation in Fedem for each time step before the stresses are output to the results database for subsequent animation The residual stress state is also output separately as a time step O for reference The Start time of the stress recovery needs to be specified greater than 0 0 when using this feature if not the residual stress field will be ignored NOTE The imported residual stress state have no influence on the dynamics simulation in Fedem Consequently any potential non linear effect cause
239. ect is normally not visible in the Fedem UI To see the base ID you have to launch Fedem in debug mode using command line option debug Then the base ID appears in curly braces in the Object Browser The additional masses may be applied in a specified local triad direction only by specifying one of the following commands in the Triad description field the commands only affects the translational mass MassDir cx cy cz MassX MassY MassZ Fedem Release 5 0 User s Guide F Beta feature documentation F 8 Sensors i where cx cy and cz defines the local triad direction the additional mass should be applied in MassX is equivalent to MassDir 1 0 0 MassYis equivalent to ZMassDir 0 1 O and MassZ is equivalent to MassDir 0 O 1 An additional mass is regarded as a virtual added mass when AddedMass mx my mz is entered in the description field of the Triad description field The additional mass then contributes to the mass matrix and inertia forces only and not to the gravitational force vector The added mass terms then equal M mx M my M mz in the local triad directions where M is the value specified in the Mass field F8 Sensors Sensors on triads can measure rotations in terms of Rodriguez rotations by entering the command Rodrig in the description field for the selected Sensor The angular quantities measured by this sensor are the
240. ecuted Fedem is started and connects to FedemSolid unless it is already running and connected If Fedem is running but is not connected to the FedemSolid session a question appears asking whether it is ok to start a new Fedem session If your intention was to use the Fedem session already running you will have to answer No and then invoke the Start or reconnect to CAD system command in the already running instance of Fedem FedemSolid can also be started from within Fedem by using the same command 2 12 5 Commands in CAD system The Fedem menu ris New Fedem Model This command creates a new Fedem model from the current assembly configuration If a Fedem model already exists for this configuration you are asked whether you want to update it or really create a new one This command also allows you to use an existing Fedem model as a starting point for the new model This would typically be a Fedem model associated with one of the other configurations in your assembly Fedem Release 5 0 User s Guide 2 41 2 Learning the Basics 2 12 Using the CAD integration If there exist Fedem models for some of the other configurations in the assembly you are prompted with a list and can chose to use one of those models as a starting point or simply choose None to create a completely new Fedem model When no associated Fedem models can be found you get the option of browsing for one Open Fedem Model ES This command simply
241. ed Gray Full Color Clipped Limits This is a mapping that is useful when you want a quick overview of the few elements in a big complex model with results within a certain narrow value domain It renders all elements outside the domain transparent i e the elements within the domain will be the only ones visible Values Above legend domain Color Invisible Within legend domain Blue Cyan Green Yellow Orange Red Below legend domain Invisible Undefined Invisible Red Blue This is a mapping useful when you want the interpolation of colors within one element face to be strictly consistent with the contour legend Because of limitations in the 3D graphics hardware interpolations of colors within one face will be linear That makes the normal full color mapping inconsistent within one face if the different nodes in the element face have values that map to colors separated by one or more colors in the legend domain Values Above legend domain Color Red Within legend domain Blue Red Below legend domain Blue Undefined Gray Contour value domain control The Max Min fields in the Animation Control dialog are used to control the domain of the color legend The defaults are Max 0 and Min O In this case Fedem uses the maximum and minimum values of the loaded contour results The Max Min fields can also be used to flip the legend scale in
242. ed time interval use external buffers fop Read output options from this file frsfile Name of solver results database file fsifile Name of solver input file fedem solver fsi gate Stress gate value for the damage calcula 25 tion MPa help Print out this help text false licenseinfo Print out license information at startup false licensepath License file directoryd src vpm Main vpmBase vpmStress lm linkId Link base ID number 0 linkfile Name of link input file Fedem Release 5 0 User s Guide E Command line options E 6 Strain rosette recovery options fedem_gage Command line option Description Default value littleEndian Use Little Endian formatting of DAC files rai1se logal Parameter log a1 of the S N curve 15 117 loga2 Parameter log a2 of the S N curve 17 146 m1 Parameter m1 of the S N curve 4 nullify start Set start strains to zero for the rosettes false rosettestrains rdbfile Name of strain gage results database file rdbinc Increment number for the results data 1 base file resfile Name of result output file rosfile Name of strain rosette input file samfile Name of SAM data file statm Start time 0 stotm Stop time 1 terminal File unit number for terminal output 6 tinc Time increment 0 0 process all time 0 steps version Print out program version false writeAsciiFiles Write rosette results to ASCII files
243. edem triads are the system model counterpart of the FE nodes and represent the connection between the system model and the links See Section 4 3 Triads and Section 3 6 Attaching and detaching elements for a description of how connections are made using triads As you assemble the model and move things around Fedem tries to help you by setting the movability of objects to match the constraining of your model This means that you will be unable to move an object such as a ball joint that is fixed in some way If an object is constrained from translating you will be able to rotate but not translate it and so on 3 0 Mechanism modeling environment Fedem s modeling environment combines a powerful 3D graphic interface and dynamic viewing capabilities with quick and easy management tools The Model Manager tabs provide shortcuts for creating selecting and deleting elements 3 2 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 2 Mechanism modeling environment 3 2 1 Modeler window To build a mechanism model Fedem provides the Modeler window a three dimensional graphical environment in which your model can be viewed and edited The mechanism elements are selected from menus and toolbars for placement in the Modeler window They can then be moved and manipulated using Fedem s modeling tools This editing environment also features dynamic viewing tools defined view commands and appearance settings see Section 2 7 V
244. eduction process for each link generates superelement mass and stiffness matrices which are then assembled into the system mass and stiffness matrices in the dynamics simulation See the Fedem R5 0 Theory Guide Chapter 3 Model Reduction for more information about Fedem s model reduction process You can initiate the model reduction process manually at any time see Section 6 3 Model reduction Alternatively you may also perform the model reduction in Nastran see Section 6 4 Model reduction in Nastran 6 1 2 Dynamics analysis The dynamics analysis provides the time history solution for all displacements velocities accelerations control system variables and derived secondary quantities such as internal reaction forces in the mechanical system that are driven by external forces and or prescribed displacements To achieve second order accuracy the dynamic solution to the full system of equations is found using Newmark time integration and Newton Raphson equilibrium iterations at each time step For the control system an implicit second order Runge Kutta method Lobatto IIIC is used with Backward Euler for local error estimation The latter is an implicit first order method See the Fedem R5 0 Theory Guide Chapter 7 Dynamics Simulation for more information about the dynamics analysis See Section 6 5 Dynamics analysis to set up and perform the dynamics analysis Static equilibrium analysis Before performing the d
245. ee Section 5 3 Control blocks for descriptions of each control block Je D D gt Ele Bale Ed Ed Fo Pale feel s Fedem Release 5 0 User s Guide 5 Control System Modeling 5 2 Input and output a Control Tools toolbar The Control Tools toolbar shown below consists of drawing and editing tools See Section 5 4 Building control modules for use of these commands iG 5 1 3 Control system topology In a similar manner as forthe structural uie mechanism the topology of the current Start block control system may be browsed in the Ihre Ne NOR Topology panel in the lower left corner Comparator3 of the Fedem main window See also Plotted by i Curve 12 New Curve Section 2 5 4 ID and Topology panel 5 2 Input and output The input and output blocks are the connections through which the BH control system and the rest of the mechanism model interact Control Input The input block is used to set up input values from the mechanism either o measurements or functions of time The options of the Control Input element is nearly identical to the options of a Function See Section 4 10 2 Function properties The output value of the Control Input is then connected to other control elements Control Output system available to the mechanism When created it will automatically be available in the various drop down menus that allow values from a control system The variable ca
246. ee Section 7 2 12 Export of Curve Data and Section 7 2 13 Importing Curves and Graphs respectively Fedem Release 5 0 User s Guide 2 35 2 Learning the Basics 2 10 Printing and exporting 2 36 Exporting the 3D modeler view To export this view make Cy New Ctrl N the window of the view Ei active and then select Bk come ce Export gt Export View from E Save Cres the File menu Save As Y Load Link Ctrl When exporting the modeler view you may choose between the Set model link repository Export Object following image formats d Print view Print View Setup ET bmp Export Animation i Exit Ctrl Q jpeg png rgb 3D inventor snapshot iv The different file formats have different quality Jpeg is a widely recognized format The compression reduces the quality somewhat but the files are small Png and bmp have better quality We recommend using the png format for high quality images The iv format enables dynamic 3D viewing of your models using an external viewer Viewers are available for several platforms Stills of animations e g contour plots can also be exported Simply pause your animation where you want the picture or 3D snapshot taken then export the modeler view Exporting graph views To export a graph view follow the steps described in the section above You may choose between these image formats bmp gt jpeg png Fedem Rele
247. ee below Result this option allows you to specify which type of result to display in the animation stress strain deformation etc The options available depend on the Result class setting and on the actual results currently available in the results database Operation this option allows you to specify the scalar value to extract from the selected result such as component selection von Mises principle values and so on The operations available depend on both the Result class and Result settings NOTE There are two ways of animating some stress and strain measures E g a von Mises stress animation may be set either by choosing Result Stress and Value von Mises or by choosing Result von Mises directly The reason for this is the option to recover the desired derived stress strain measures directly see Section 6 6 1 Stress recovery options In the above example if the entire stress tensor was recovered the first animation definition would be correct If only the von Mises stress measure was recovered the second definition should be used Choosing the wrong definition would leave an empty animation Result Set These options allow you to select one of the named result sets for the Result class node element or element node you selected This setting is used to distinguish between multiple results for the specified FE entity including results from different layers 7 26 Fedem Release 5 0 User s Guide
248. eel speeds is shown in Figure B 6 B Using the SWIFT Tyre Model B 3 Force Evaluation Figure B 6 Wheel Load as Function of Tire Deflection at Different Wheel Speeds Normalised vertical load 1 nominal load 0 0 5 1 1 5 2 Normalized tyre deflection 1 is nominal load at standstill Figure B 7 SWIFT with Bottoming Characteristics BOTTOMOFFST H BOTIOM_TRNSF SWIFT incorporates bottoming effects for load case studies as shown in Figure B 7 Bottoming occurs when the deflection of the tire results in Fedem Release 5 0 User s Guide B 13 B Using the SWIFT Tyre Model B 3 Force Evaluation contact of the tire tread band with the wheel rim a radius that generally will be somewhat larger than the rim radius RIM_RADIUS The assumption is made that the bottoming characteristics are independent from the normal vertical spring curve Three parameters are required to define the bottoming characteristics BOTTOM STIFF Defines the linear vertical stiffness of the tyre wheel assembly when the tyre is bottoming As a first estimate a value of ten times the vertical stiffness may be appropriate BOTTOM OFFST Defines in combination with RIM_RADIUS the maximum radius where bottoming can start to occur see Figure B 7 The actual point where the vertical force starts to increase is the point of intersection between the normal vertical spring and bottoming spring curve BOTTOM T
249. efinition 7 2 restrictions 2 18 graphing options 7 2 objects modes 6 34 related 2 11 power block 5 4 selection history 2 18 Print View button 2 35 Objects list prismatic and cylindric joints 4 31 functions 4 51 improving load distribution 4 31 Objects tab 2 10 prismatic joints 4 31 option files adding friction 4 31 storage 8 9 Pro ENGINEER 1 4 Origin property 3 10 3 13 processing results output block deleting 6 48 definition 5 3 Fedem Release 5 0 User s Guide Index l 9 I 10 Index storing 6 48 program modules 1 5 strain rosette analysis 1 7 properties 2 12 Property Editor panel 2 7 2 12 Property menues 2 13 R rack and pinion 4 38 transmission ratio 4 38 Radial contact 4 36 rainflow analysis 6 42 real pole block 5 7 recovery operations deleting result files 6 48 Red Blue 7 37 reducer options E 2 Reference 2 27 Reference Plane 3 4 changing appearance 2 27 3 4 References for MF Tyre A 40 relations 2 11 relative sensor 4 65 remove breakpoint 5 10 resolution settings 2 2 2 34 result directories 8 10 result set by name 7 26 by operation 7 26 results file types D 3 results files 8 9 Results list managing 7 2 shortcut menus 7 2 Results tab 2 10 revolute joint 4 27 rgb format 2 35 Right view 2 22 rigid body animation 6 33 6 34 6 47 rigid joint 4 28 rigidity symbol 3 11 Road 4 49 4 53 Road input for SWIFT Tyre B 14 Road property files examp
250. efinitions VVVVYVVVVYVYVY References Fedem Release 5 0 User s Guide A 1 A Using the MF Tyre Model A 1 About MF Tyre A 1 A 2 A 2 About MF Tyre The MF Tyre model uses a method known as the Magic Formula to calculate the steady state behavior of a tire The Magic Formula is actually a set of mathematical formula based on the physical background of the tire road and the tire to road contact The Magic Formula tyre model aims at an accurate description of the steady state behavior of a tyre by providing a set of mathematical formulae which are partly based on a physical background The Magic Formula calculates the forces F Fy and moments M My M acting on the tyre under pure and combined slip conditions using longitudinal and lateral slip k a wheel camber g and the vertical force F as input quantities In addition to the Magic Formula description a set of differential equations is defined representing the transient behavior of the tyre with respect to handling at frequencies up to 8 Hz Further information can be found on the internet site www delft tyre com MF Tyre Version 5 2 Compared to MF Tyre 5 1 following items have been changed or introduced The scaling factors for the shifts have been defined such that conicity and plysteer effects can be easily switched off Into the modelling of combined cornering and braking traction E factors have been introduced making the modelling
251. elect which road you want the tire to run on Do that by selecting the correct road in the Road drop down menu gt Tire model The tire models currently available are MF tyre delivered by TNO Appendix A Using the MF Tyre Model SWIFT tyre developed by TNO Appendix B Using the SWIFT Tyre Model FTIRE developed by Cosin Consulting www ftire com Z offset If the wheel bearing joint is not located in the mid plane of the wheel this can be accounted for by setting the Z offset to the distance between the wheel mid plane and the bearing joint 4 9 2 Road The road surface is defined by either a Road elevation function or by a d road definition file Currently roads defined by a function can only be used by TNO tires MF Tyre and SWIFT while road definition files can only be used by the FTIRE tire model The Property Editor panel for a road is shown below Description Road 00 T Road definied by function 0 Road function Noe s C A Rotation about Z axis OO l Vertical shift 00 Horizontal offset o C Road defined by file Road file Fedem Release 5 0 User s Guide 4 49 4 Mechanism Elements 4 10 Functions 4 9 3 4 10 4 50 select the Road elevation function that describes the road surface o The road alignment vertical shift and horizontal offset can be adjusted for the individual roads when defined by a Road elevation function The road alignment a
252. elects all the nodes from the FE model in question that is on the surface of the cylinder volume defined These nodes is now connected to the new or existing triad by the Surface connector Deleting or redefining Surface connectors A surface connector is actually an attribute of the Triad it connects This means that if the triad is detached the connector is deleted If a connector needs to be edited or changed simply use one of the Surface Connector commands to redefine it Invoke the commend and select the triad with the misdefined connector at the start of the command sequence 3 6 4 Attachment rules and restrictions There are several restrictions and rules that apply to the connections between FE models and triads These restrictions do not apply when the link is a Generic Part Triads can not be attached to 3 DOF FE nodes To attach a triad to a solid model you need to add an element and create a 6 DOF node at the correct position TIP Normally a weighted average motion element Nastran RBE3 or a rigid element Nastran RBE2 will be a good way to create a 6 DOF node at a hard point position on a solid mesh gt The triad and the FE node must be within the distance set by the modeling tolerance see Section 3 9 2 Modeling tolerance If several 6 DOF nodes exist within the modeling tolerance the one closest to the triad will be selected Slave triads can not be attached to ground Joints must be attached to the gr
253. element statements parameters C 4 equilibrium analysis conditions 6 25 error messages intepretation 6 51 example control system 5 2 exporting 3D modeler view 2 36 animations 2 35 2 37 curves 2 35 Index l 3 l 4 Index graphs 2 35 2 37 7 20 links 2 35 objects 2 35 External Control System 1 4 external control system 5 11 Simulink 5 11 external nodes 1 4 F F1 dynamic pan 2 20 F2 dynamic zoom 2 20 F3 dynamic rotate 2 21 F4 select dynamic center 2 21 fatigue analysis 6 43 Fedem 2 7 about 1 2 2 1 binary input blocks 5 4 building techniques 3 2 commands 2 1 control systems 5 2 available control elements 5 4 controllers 5 6 definition of 1 2 directory structures 2 3 8 8 editing environment 5 2 file formats D 2 file types 2 3 input D 2 intermediate D 2 results D 2 secondary D 2 file use overview D 4 files and directory structures D 1 graphical representation 5 2 main window 2 6 major user tasks 3 3 mechanism 1 4 analysis 6 1 elements 3 1 model definition of 1 4 modeling environment 3 2 module execution 1 5 reducer options E 2 results database removing unwanted files 8 9 starting 2 4 strain rosette analysis 1 7 technical support 2 6 user interface 2 1 2 6 Fedem Link Model 1m format C 1 Fedem Mechanism Model fmm format 2 3 Fedem Technology Link t 1 format C 1 C 2 nodes C 3 FE Fatigue 6 43 license 6 44
254. em 1 7 Fedem solver modules Ce 1 7 1 Reducer The Fedem Reducer performs a super element reduction of the FE model representing the mass and stiffness of a link A super element reduction reduces the required DOF to a minimum The retained DOFs also called external DOFs are the results of a dynamic super element reduction technique called Component Mode Synthesis reduction also known as CMS reduction More information on this topics can be found in Finite Element textbooks 1 7 2 Dynamics Solver The Fedem Dynamics Solver module performs a nonlinear dynamics simulation This means a simulation of the motion and deformations of the Super Elements and the Joints as they respond to load and displacement time histories and Control System output In any time step of the simulation the model can be linearized whereby an eigenvalue analysis can be performed Link deformations and mode shapes are recovered by the Stress Recovery module and Mode Shape Recovery module 1 7 3 Stress Recovery The Fedem Stress Recovery module recovers the internal DOFs from the deformations of the external DOFs simulated by the Dynamics Solver The element stresses strains and beam forces are then calculated 1 7 4 Mode Shape Recovery The Mode Shape Recovery module recovers the links mode shapes from Eigen values calculated in the Dynamic Solver 1 75 Strain Rosette Analysis The Fedem Strain Rosette Analysis module recovers the stresses and strain
255. em model retains the FE characteristics of its component links and can therefore be treated as a geometrically nonlinear Finite Element model The mechanism is then allowed to experience large translations rotations and nonlinear behavior dependent loads in the simulation of its dynamic motion Functions measured time history input data and control systems can be used to model virtual test events by controlling loads motion spring lengths etc Fedem s solvers can then calculate the motion kinematics dynamics structural flexibility stresses strains and varying loads in one consistent model 1 5 Using FE models Fedem imports FE models created in external systems by interfacing with the MSC Nastran Bulk Data File bdf and nas format see Section 4 1 1 Creating links by file import Many FE modeling systems including I DEASS Pro ENGINEERS Altair HyperMesh NEiWorks NEiFusion and MSC Patran can export data to the Bulk Data File format enabling you to use your favorite FE modeling program with Fedem 1 4 Fedem Release 5 0 User s Guide 1 Introduction to Fedem 1 6 CAD integration Es Fedem can also import models which are saved using the ABAQUS inp format and the Ansys anfand cdb format Each FE model must include descriptions of its nodal coordinates element topologies element properties material data nodal attributes and so on The results obtained in the simulation depend to a large extent o
256. ements Memory usage is the most crucial point and can be reduced to 1 3 when using the better options mentioned below The significant parameters are in order of decreasing importance 1 Whether result set selection is By operation or By name By name is better 2 Whether Load face contours and or Load line contours are toggled Only load face contours is better 3 Whether averaging is turned on or off No averaging is better The number of elements visible when the animation is loaded is also important because result values will only be loaded for visible element faces This means that you can load contour data for one group at a time if loading data for the complete link is too memory and time consuming 7 4 Viewing animations When an animation is loaded you can use several tools to view and explore the data you have loaded The modeler window will display some 7 32 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 4 Viewing animations additional features and the Animation Control window will be made available These windows are shown in the figure below Camera Time 0 03900 Reference Lik None z Motion IV Show Link Motion Step 9 Deformations IV Show Link Defermation Seale 3 00 r Contour Legend Show Contour FF Show Legend Colors Full color 4 i gt Mapping Linear Look Smooth x 4a ra 9n E Min 00 Slow Real Fast Tick Matks c
257. ened model file contains results information about the result files in the model rs files is reported in the Output List window However results files belonging to unloaded links see Section 2 9 Loading and unloading FE Data and disabled result files see Section 8 2 2 Result manipulation are not included in this report If any problems are encountered during model loading Fedem displays an alert message box and provides additional information in the Output List window NOTE There might be minor changes in the model file format from one Fedem version to subsequent versions of Fedem The newer versions are always backward compatible such that you may safely open a model that was created in one particular version in any of the subsequent versions without loosing model consistency The model is automatically converted to the new format while reading it CAUTION The Fedem model files are not necessarily forward compatible If you open a model in an older version of Fedem than it was created in there might be changes in the model file format that makes the imported model incorrect or inconsistent In some cases it may also make the Open operation fail or hang Refer to the Fedem R5 0 Release Notes Chapter 3 Notes for a summary of the forward compatibility issues that might need to be manually resolved in such cases Loading links When Fedem opens a model file and the loading of FE data is enabled the link information
258. ent toggle off Use Thickness from FE Mesh and enter the new position above the element mid plane set start strains to zero This toggle will zero out the strains at the first time step eliminating strains due to gravitation or prestress effects when using the optional initial equilibrium iteration see Section 6 1 2 Dynamics analysis and Section 6 5 1 Dynamics Solver Setup Q Material The stress calculations will normally use the material data from the FE mesh If those values are inadequate for some reason they can be overridden by toggling off the Use material from FE Mesh toggle and enter proper values for E Module and Poisson s ratio Fedem Release 5 0 User s Guide 4 67 4 Mechanism Elements 4 12 Strain rosettes 4 68 Fedem Release 5 0 User s Guide 5 Control System Modeling pom M Chapters Control System Modeling Real mechanisms are often connected to or acted upon by control elements such as sensors controllers and actuators A control system is therefore necessary to simulate these effects for Fedem mechanisms This chapter describes the control elements available in the Fedem Control System library and explains how to model your control systems In addition to the internal control system a connection to MATLAB Simulink models is enabled through a MATLAB plug in module A description is given on how to link this type of external control system to the Fedem model Sections in this chap
259. entation and a snap point If the face or edge in question is a revolved geometry the options shown to the left pop up Ie REA in the Guide panel These options allow you to control how the snap point amp Snap to vertex and the default orientation is extracted from the geometry xe Flip direction r a n First of all you can choose whether the point shall snap to the center axis of the revolved face On Center with the default orientation along the axis or to the circumference of the revolved geometry On Circumference with the default orientation perpendicular to the face The default orientation can be flipped to the opposite direction using the Flip Direction option The Snap To Vertex option controls whether or not the selected point shall snap to the closest vertex If you have chosen On Circumference the point will snap to the closest vertex on the surface If On Center is chosen the point will snap to the point on the center axis which is closest to the vertex Default direction notes The default direction is visualized as a yellow arrow starting from the selected point The different object types utilizing the default direction and how they use it are listed here Force and Torque the attack direction Revolute joint the axis of rotation Cam joint master triads the x direction up of the masters are aligned with the default direction O Y VYY Free joint Z Axis of the master Fedem Release 5 0 Use
260. eometric Stiffness Contribution in initial equilibrium iterations see the similar option in the Integration tab The Equilibrium iteration tolerance is the convergence tolerance on the norm of the iterative displacement correction during the equilibrium iterations equivalent to the Scaled vector norm tolerance for Displacement iteration correction in the Tolerances tab The Iteration step size limit is an upper limit on the norm of the displacement correction vector within one iteration If the norm is higher than this value the correction vector is scaled down such that its norm equals this number Each time this happens the iteration counter that is compared to the Maximum and Minimum Number of Iterations parameters of the Integration tab is reset to zero NOTE Maximum and Minimum Number of Iterations set in the Integration tab also apply in the Initial Equilibrium analysis TIP The defaults for the Equilibrium Iteration Tolerance and Iteration Step Size Factor are usually acceptable However if the mechanism is modeled far from the equilibrium position reducing the Iteration step size limit may improve performance Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis CAUTION The Iteration step size limit must always be larger than the Equilibrium Iteration Tolerance CAUTION To perform the equilibrium analysis you may have to apply Additional Boundary Conditions before startin
261. equently used with arguments k and a from Equations A 90 and A 91 instead of the longitudinal and lateral wheel slip quantities k and a Equations A 9 and A 10 F F a F A 92 F F a y F A 93 M M a y F A 94 A 6 5 The Gyroscopic Couple This moment due to tire inertia acting about the vertical axis reads dv M gyr CgyrMpettV rr gp 008 arctan B a eq A 95 with parameter in addition to the basic tire parameter mpg Coyr aT Nig A 96 and cos arc tan B a gy 1 A 97 for pure cornering conditions The total aligning torque now becomes M M M oyr A 98 A Table A 17 Coefficients Transient Response Name Ta eoe a e Explanation Pd PTX1 Relaxation length SigKapO Fz at Fznom PTx2 PTX2 Variation of SigKapO Fz with load PTx3 PTX3 Variation of SigKapO Fz with exponent of load Pryi PTY1 Peak value of relaxation length Sig_alpha Fedem Release 5 0 User s Guide A 31 A Using the MF Tyre Model A 6 Steady State Magic Formula A 32 A 6 6 Table A 17 Coefficients Transient Response Name al eil Explanation Pty2 PTY2 Shape factor for Sig_alpha Qrz1 OTZ1 Gyroscopic torque constant Mpeit MBELT Belt mass of the wheel Switching from a Simple to a Complex Tire Model MF Tyre enables the user to switch from a simple tire model for example only calculations for steady state pure cornering
262. er Adding friction You can add friction to prismatic joints by selecting one from the list of frictions in your model in the Friction pull down list located on the Property Editor panel See also Section 4 6 Frictions and the Fedem R5 0 Theory Guide Section 6 5 Joint Friction Fedem Release 5 0 User s Guide 4 31 4 Mechanism Elements 4 4 Joints Cylindric joint ti A flexible cylindric joint has four unconstrained DOFs that allow both translational displacement along the local z axis and rotation about the local z axis As with prismatic joints cylindric joints do not constrain motion in the other two rotational directions The joint s local coordinate system is defined in the same manner as for the prismatic joint The cylindric joint has two joint variables They are the translational distance along the local z axis from the first master to the slave the slider variable and the angle of rotation of the slave about the local z axis The rotation angle is measured between the x axis of the first master triad and the x axis of the slave triad The symbol for a flexible cylindric joint is displayed in the Modeler as shown below First master triad The slider path represented by the line from the first master to the last e Rotational joint variable represented by the angle of the x axis Slave triad Last master triad You can constrain the two joint variables of Screw connection a cylin
263. eral additional options exist The results data from a dynamics analysis is divided into primary and secondary variables The primary ones consist of triad and superelement link position matrices and if any generalized displacements for super elements having component modes All other variables are secondary variables The output frequency accuracy and the amount of these variables may be controlled using Additional Solver Options for the Dynamics Solver see Section 6 2 3 Additional solver options These options are discussed below Refer to Appendix E Command line options for a complete list of solver options Output start up time Before presenting the options to format the output we note that the time of output start up may also be controlled This is done using the savestart solver option The option applies to both the primary and secondary variables as well as internal control system data savestart Time for first save to response database NOTE The default value of this option is 0 0 Therefore if you are using a Start time less than zero and want to save the results also for the time steps with physical time less than zero you have to specify savestart start time as an additional solver option for the Dynamics Solver 6 26 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 5 Dynamics analysis Es Output frequency Primary variables are output for all time steps of a dynamics simulation and
264. ession allows a user defined function expression to be entered as free text The function is entered in the Parameters section of the Property Editor panel as shown below The Apply button must be pushed to check and register the expression entered r Function Type Parameters Parameter Help Preview Math expression z sin x abs x lt 0 1 x abs x gt 0 1 Argument 1 CtDut DOF z Var M Enter a function of x Apply Fedem Release 5 0 User s Guide 4 55 4 Mechanism Elements 4 10 Functions 4 56 Rules for Fedem math expressions The expression must be mono variable and the independent variable must be named x The expression may only consist of the intrinsic functions and operators listed below along with the independent variable x Both x and other functions may be used as function input E g sin cos x is a valid expression Precedence is set by parentheses in the usual manner E g sin x 2 xis squared before being input to the sine function sin x 2 the value of sine of x is squared The logical operators have a return value of 0 if FALSE and 1 if TRUE and are used by multiplying them with the function expressions E g Sin x x gt 2 x equals sin x if x lt 2 and sin x x if x22 Below are the available intrinsic functions and operators The symbo
265. et to Surface or Surface and Internals or when color contour results are loaded for the link This feature can also be utilized to load color contour results only for small parts of a big link because the color values will not be loaded on hidden elements See also Section 7 3 4 Performance of animation loading NOTE The visibility of the mesh is not affected by the Show Hide commands Visualization of special finite elements There are several finite element types that are treated differently from normal elements like shells and solids when it comes to visualization Those elements are listed in the table below Table 2 1 Line style of special finite elements Element type Visualization Comments Beams Dash dot lines The eccentricity is ignored in the visualization Rigids Dashed lines Constraint elements Dotted lines RBE3 WAVGM Distrib uted coupling Concentrated mass No visualization Springs No visualization Bush elements No visualization Fedem Release 5 0 User s Guide 2 Learning the Basics 2 8 Opening and saving model files Color The color of those elements are set automatically to black white or a grayish color to achieve a good contrast to both the color of the link and the viewer background If the FE part is displayed using lines only the color of those elements is set to the color of all the other lines Line width The line width is adjusted according to the L
266. f the first curve in the selection Subsequent curves having a lower resolution in their data sets will then be interpolated where needed if they have a higher resolution some data points will be omitted in the exported graph When exporting to MTS RPC III the constant increment Ax for the graph is selected as the smallest increment between two data points among all the selected curves Curves having a lower resolution than this increment will then be interpolated where needed TIP To export a single curve or graph you may also use the Export and Export Object item in the File menu after selecting the desired curve or graph 7 2 13 Importing Curves and Graphs Curve data can be imported into Fedem both as single curves and complete graphs Importing Curves To start importing curves right click with your Result selector mouse on a graph a curve or on an empty spot E wave in the Model M Results list and sel alae in the Model Manager Results list and select Sil Gen ries Import and Import Curves In the file dialog that mjsesesh cuit pops up select one or more files you want to import ort Curves import One curve is created from each file you S pure Sah ort by have selected eun Delete Del If you right clicked on a curve or a graph the curve data will be imported into that graph Importing Graphs To start importing graphs right click with your mouse anywhere in the Model Manager Results Lis
267. fatigue solver the Analysis type is always Signed abs max stress S N When using the nCode fatigue solver see Footnote 1 you may choose between Signed abs max stress S N and Signed abs max strain E N as the analysis type Q Stress Strain range threshold You may set a gate value for the Peak valley extraction That is only the stress strain ranges with magnitude higher than this value will be included in the peak valley extraction You may set the Histogram Range values and number of bins to be used in each axis direction for the rainflow analysis only for nCode fatigue analysis see Footnote 1 To perform rainflow and fatigue analysis during the strain coat recovery you also need unless nCode is used to assign an S N curve to base the damage calculation on for each element group you want to consider in the fatigue analysis This is performed in the Property Editor panel for the element groups see Section 4 2 1 Element group properties 6 9 3 Import of residual stresses from external analyses Similarly as in the Stress Recovery see Section 6 6 3 Import of residual stresses from external analyses you may superimpose a constant residual stress state on the computed dynamics stress field before calculating the strain coat summary quantities for S N analysis This feature will thus be enabled if you have specified an external results file with such residual stresses in the Advanced tab of the Property Editor panel for
268. ference plane in the Modeler window and press Done to confirm the selection The object becomes attached to the selected link or to the ground if the reference plane was selected TIP Watch the Output List for error messages during the attachment process If Fedem cannot complete an attachment an error message is displayed in the Output List NOTE Triads in axial springs dampers and loads are automatically attached when created because the orientation of such triads is not important Attaching joints Joints consists of one slave triad and one or more master triads The slave triad is normally attached to one FE model and the master triad s to another This is done by attaching one part of the joint first and then the other one See Section 4 4 Joints for more information about master and slave triads in joints When attaching by selecting the joints directly Fedem automatically selects which triad master or slave to attach first In most cases the slave is attached first To control whether a joint s slave or master is attached to a specific node select only the part of the joint symbol that represents the particular master slave triad when selecting the object to attach during the attach 3 16 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 6 Attaching and detaching elements pm M command See Section 4 4 Joints for more information about joint symbols UT TIP To attach multiple joints to a sing
269. ffects and belt dynamics become important for the forces transmitted by the tire to the wheel centre SWIFT combines a Magic Formula slip force calculation with a rigid ring model thus greatly extending the frequency range where the tire model is valid The SWIFT Tyre model was developed in a joint cooperation between the Delft University of Technology and TNO Automotive under the guidance of Dr Pacejka Reference documentation can be found in Section B 1 4 References Dynamics The SWIFT Tyre model is a rigid ring model in which the tire belt is assumed to behave like a rigid body This means that the model is accurate in the frequency range where the bending modes of the tire belt can be neglected which depending on the tire properties is up to 50 60 Hz for lateral behavior and up to 100 Hz for vertical and longitudinal behavior SWIFT has been validated using measurements of a rolling tire 7 to 40 m s containing frequencies up to 120 Hz The model includes essential gyroscopic effects Slip Force Calculation SWIFT uses the Magic Formula for calculation of slip forces providing an accurate representation of measurement results which usually are available up to 15 degrees side slip 10096 brake slip and 5 degrees of camber angle for different vertical load For efficiency reasons SWIFT uses a single point contact for slip calculation and therewith is fully compatible with MF Tyre Due to the introduction of a so called phase lead
270. ficients Transient Response Name used in tire Name property file Explanation E LSGKP Scale factor of Relaxation length of Fx Gd LSGAL Scale factor of Relaxation length of Fy Ngyr LGYR Scale factor of gyroscopic torque Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula A 6 Steady State Magic Formula A 6 1 Steady State Pure Slip Formula Longitudinal Slip Pure Slip Figure A 9 Longitudinal Slip Condition Pure Braking Traction F Fyo F Fo D sin C arctan B K E B k arctan B Sy K K Syy d ang with coefficients C Poxi hex D m AF 2 Hy Ppx1 Ppyadf a d Ppx3 Yx Xx 2 E C ga Pgyadf Pgyadf E P px4580 K Nel lt 1 K E F i Gi Px exp P kx3dfz i Aky A 16 A 17 A 18 A 19 A 20 A 21 A 22 A 23 A 24 A 18 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula se OF k BCD at K 0 OK B K C D A 25 Si 7 Una Par dg A 26 Sy Fe ya Pyaldf 2 Ayx Ayx A 27 Table A 9 Longitudinal Coefficients Pure Slip Name Supers tile tire Explanation Pox PCX1 Shape factor Cfx for longitudinal force Ppx1 PDX1 Longitudinal friction Mux at Fznom Ppx2 PDX2 Variation of friction Mux with load Ppx3 PDX3 Variation of friction Mux with camber
271. fining properties 4 1 changing appearance 2 27 deleting from model 3 22 duplicating 4 6 detaching 3 21 exporting 2 35 fully constrained 3 11 importing 2 8 4 3 limiting display of 2 18 importing several at once 4 4 links 3 8 proportional damping 4 8 measuring movement and link wise solving 6 9 variables 4 64 load fringes 7 23 moving 3 10 loads 4 46 viewing and editing properties 2 12 load target point 4 47 mechanism entities loads and torques display manipulation 2 25 control of magnitude 4 46 mechanism mode shapes logical switch block 5 5 animating and displaying 6 33 lumped mass matrix 6 12 mechanism model building 3 1 3 3 M mechanism symbols 2 25 manipulating appearance 2 24 Magic Formula Mechanism Tools toolbar 3 4 about MF Tyre model A 11 menus and toolbars 2 7 mass and stiffness matrices 6 2 MF Datasets master slave triad 4 20 described for MF Tyre A 36 attaching manually 4 20 MF Tool described A 36 MATLAB Simulink 1 3 MF Tyre MATRIXx 1 3 about Magic Formula A 11 mechanism 1 4 about tire model A 2 3D view of 2 14 axis systems in A 5 accessing a response variable 5 3 contact point C and normal load A 7 building 3 4 described A 2 components formula for gyroscopic couple A 31 flexibility of 1 3 history A 11 element connections 1 4 learning basics A 13 introducing motion 4 46 lists of definitions A 38 modeling process 3 1 references A 40 Fedem Release 5 0 User s Guide Index
272. from time to time In the model reduction process this will typically result in a singular mass and or stiffness matrix Fedem recognizes two types of singularities which are handled slightly different in the matrix triangularization factorization gt DOFs that have not received any stiffness mass contribution at all and thus have an exact zero pivot before the triangularization is started are detected a priori The zero pivot is then replaced by the value 1 0 which implies that the singular DOF is constrained to zero DOFs that initially have a non zero pivot but are reduced to a value close to zero during the triangularization will receive some small 1 You have constraint equations in the link if it contains RBAR RGD WAVGM RBAR RBE2 RBE3 in Nastran terminology and or BEAM elements with end release Thus as the number of such elements in the link increases the advantage of using lumped mass will decrease 6 12 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 3 Model reduction value on the diagonal allowing the triangularization to continue for the detection of other potential singularities The judgement on whether such singularities have occurred is based on the user provided Singularity tolerance see below When the reduction process has terminated a list of all singularities is written to the Output List and the res file Each singular DOF is here identified by the node ID and local DOF numbe
273. g and saving model files Loading and unloading FE Data Printing and exporting License information VVVVVVVVYVVYVY Using the CAD integration Fedem Release 5 0 User s Guide 2 1 2 Learning the Basics 2 1 System requirements 2 2 2 1 2 2 System requirements The following are minimum system hardware requirements and recommended settings for optimal Fedem performance NOTE Use of resolution settings other than those recommended below may require you to move or resize windows and dialogs to fit your screen Table 2 1 Windows 2000 XP Vista and recommended settings Processor Recommended Pentium 4 2 GHz Minimum Pentium Ill 850 MHz Recommended 2 GB RAM Minimum 256 MB Free disk Dependent upon the size and complexity of space mechanism models Graphics Recommended high end graphics card card Required OpenGL API support Pointing Three button mouse with wheel device Resolution 1 280 x 1 024 pixels or higher setting Larger models may require several GBs Software requirements Fedem interacts with other softwares in different ways To utilize these integrations you need the correct versions of those 3rd party systems The following versions of these softwares are supported by Fedem CAD integration SolidWorks 2008 32 bit Optionally with the NEiWorks 1 4 2 add in NEiFusion 1 4 2 32 bit nCode fatigue integration nSoft 5 3 1 FE Fatigue 5 IS
274. g file references in mechanism elements 2 To remove the element s from the model right click and select Delete from the shortcut menu or hit the Delete key The items are removed from both the model and the list at the same time NOTE When deleting Links you have the option to retain triads that are attached to each deleted link except for joint triads they are always retained to also delete those triads or to cancel the Delete command If no such triads exist for a selected link you must anyway confirm the deletion of the link This choice must be made for each link in the selection However by selecting the Yes to all No to all or Ok to all button you automatically repeat the same choice for each link in the current selection NOTE If any of the objects you delete are referred to by a curve you will be able to choose to either delete that specific curve definition leave the curve definition intact while still deleting the object or cancel deletion of the selected object WARNING If the deletion of a selected object also causes deletion of other objects t connected to it and any of these other objects also are referred to by a curve you will be notified and can choose whether to delete that specific curve definition or not too However you can not choose to cancel the Delete operation at this stage 3 8 Using file references in mechanism elements Some mechanism elements in Fedem need input from external files
275. g the dynamics analysis For information about applying such boundary conditions see Section 4 3 3 Triad properties Output tab On this tab you can control the automatic curve and animation export from the Dynamics Solver to file The automatic curve export is useful if you want to run Fedem in an iterative loop with some external software and need to process selected solver output in order to calculate new input for subsequent runs The automatic animation export writes a GLview VTF file with the rigid body motion of the computed response This file may then be opened in the Ceetron GLview software for further viewing see www ceetron com for further details on GLview This toggle enables export of all curves in the model with Export curve automatically Dy nena curve eet toggled on in the Property Fie exported_curves sp Editor panel see Section 7 2 5 Curve eae xpress File properties 2 This field shows path and A Automatica start a simultaneous Rigid Body animation on solver stat name of the file the curve data will be written to Press the Browse button to change file name or file format This label shows the selected format for the curve export Available formats are MTS RPC UNIX or PC formatting and tab separated multi column ASCII Dynamics Solver Setup Time Integration Tolerances Eigenmode Initial Equilibrium 4 Automatic export to GLview VTF file Only curves plotting results
276. global setting defined in the Integration tab of the Dynamics Solver Setup is used see Section 6 5 1 Dynamics Solver Setup On Turns centripetal force correction on for this link Off Turns centripetal force correction off for this link Q By enabling this toggle you may browse for an external result file from which a residual stress state is imported in the Stress and Strain Coat recovery processes The supported file formats are SDRC universal file unv ABAQUS result file i 1 ANSYS result file rst rth NASTRAN Output file op2 See Section 6 6 3 Import of residual stresses from external analyses for further details on the usage of this feature 4 1 5 Usinglink repositories A link repository is a directory structure containing all the files related to one or more FE links This includes the finite element model files reducer input option files the reduced matrix and load files the displacement recovery matrix files and log files with text based output from the link reduction processes The term link database is also used when referring to a link repository For detailed information about link databases see Section 8 3 1 Link database Fedem can handle the storage of a link repository in three different ways 4 14 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links gt Internal link repository default The default link repository is placed inside t
277. gs Specifying any such option also in the Additional Solver Options dialog will then override the setting in the Setup dialog and should therefore be avoided Consult Fedem technical support if you are in doubt on the usage of a particular command line option NOTE If you mis spell a command line option in the Additional Solver Options dialog or specify options that do not exist the solver process will run as if the invalid options were not specified A warning for each unrecognized option is issued in the Output List in that case after the solver process has terminated Optimizing the Link Reducer memory usage Perhaps the most memory critical solve process in Fedem is the Link Reduction for large models On 32 bit platforms the amount of in core memory that one process may address is 2 GB usually the practical limit is lower due to other processes sharing the same CPU In Fedem a linear equation solver is used in the Link Reducer which works out of core when necessary This makes it possible to solve much larger FE models on a 32 bit platform than would be possible using an in core solver The equation solver reserves an in core buffer cache for the numerical data of a certain size and goes out of core only when this buffer is not large enough The performance of the equation solver depends on the size of this buffer and it may therefore be optimized by fine tuning this size The default is to let the Link Reducer Link Reducer
278. h B 8 4 D 0 27 and F 0 045 Table A 4 Effective Rolling Radius Parameters Name indici e tire Explanation Fzo FNOMIN Nominal wheel load B BREFF Low load stiffness eff rolling radius D DREFF Peak value of effective rolling radius F FREFF High load stiffness effective rolling radius A 10 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre H A 4 5 Tire Slip Quantities Figure A 7 Slip Quantities at Combined Cornering and Braking Traction Vsx V V Vs Um The longitudinal slip speed is defined as Vex V OR A 7 and the lateral slip speed Vy V A 8 TT A 9 t ue A 10 ana E rd with Vx and V the components of the slip speed which may be defined as the velocity of point S in the W axis system see Figure A 7 With Q denoting the rotational speed of the tire the linear rolling speed becomes Vi RQ A 11 r e A5 The Magic Formula Tire Model MF Tyre A 5 1 Introduction For a given pneumatic tire and road condition the tire forces due to slip follow a typical characteristic The characteristics can be accurately approximated by a special mathematical function which is known as the Fedem Release 5 0 User s Guide A 11 A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre A 5 2 Magic Formula The parameters in the Magic Formula depend on the type of the tire an
279. h are displayed in the Property Editor as shown below Desioen QD 4 gt Title e 3 31B 3 Grid hme IO Sub title 3 r Legend 009 Axis label eo o o lv Autoscale Y Axis label i9 Start time 0 0 Stop time 1 0 Use time intewal Description An optional user specified description that is displayed as both the graph name in the Results list and the title of the associated graph window in the Workspace area It is recommended that you use a descriptive name or phrase to distinguish between similar graphs This name is not included in the graph view itself Title You can specify a title for the graph that is displayed in the graph view 7 6 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs 7 2 5 o o 9 e Subtitle You can provide a subtitle that is appended underneath the Title in the graph view X Axis Label You can provide a label for the abscissa that is displayed in the graph view Y Axis Label You can provide a label for the ordinate that is displayed in the graph view Grid You can specify the type of grid coarse fine or no grid for the graph by selecting from the Grid pull down list Legend You can add a legend to the graph by enabling the Legend option The legend names you specify for each curve are used in the legend see Section 7 2 5 Curve properties below Autoscale Enabling this option automatically scales the
280. h program Module cece eee cence eee D 4 Command line options Fedem UI Options fedem cece cece cence nee eenenns E 2 Link reducer options fedem_reducer cece cence cence eee E 3 Dynamics solver options fedem_solver ce eee eee e ee E 6 Stress recovery options fedem stress e cece eee e ee eee E 12 Mode shape recovery options fedem modes E 14 Fedem Release 5 0 User s Guide XV E 6 E 7 E 8 Appendix F F 1 F 2 F 3 F 4 F 5 F 6 F 7 F 8 F 9 F 10 F 11 F 12 Strain rosette recovery options fedem gage E 16 Strain coat recovery options fedem_fpp ce cece eee E 18 Curve export options fedem graphexp s sese E 20 Beta feature documentation dj f P F 2 F 1 1 Universal Joint i necis ee Ip rere e pe EDI Er ead F 2 F 1 2 Constant Velocity Joint lssssssesssesseseeese mee F 2 F 1 3 Rigid JOING ive bitrate E E hades ht ert HYPE I det RN F 3 F 1 4 Axial Joint 12 b Linie Sot ie PACA Aa UPRLULD IUBE ada F 3 F 1 6 Prismatic Joint and Cylindric Joint 0 cece cece cece nen eee ee F 4 F 1 7 CaM JOIN 2355 vasa P et re hoes one RE EX ia p RE eee ea A E RUE F 4 LINKS rette tos eA att eaa Aran Aree ae a deere F 5 F 2 2 Component MOdES cece cece cece ee een cnet em eee F 5 SPRINGS 202 deep eu et ee vat ese peer rU A dud F 6 FCO E
281. he General Appearance button to display the window Mechanism symbols allows you to toggle on off the display of mechanism elements edit the color used to specify each item type and change the size of symbols and line widths see Mechanism symbols below Default colors controls the colors used for Grounded triads unattached mechanism items and the modeler background see Default colors below Q viewer options controls 3D rendering options such as visibility transparency type and line smoothing see Viewer options below Mechanism symbols This area provides the following controls Visible Enables disables the display of each item type Click the box next to an item type to change the setting General Appearance Mechanism symbols Visible Joints Springs D ampers I Gears Loads Sensors Strain rosettes Triads Stickers Tires Links Link coordinate systems I I I I I I I Local coordinate systems V Reference Plane Size 0 1 Line width Default colors Grounded triads Unattached symbols Modeler background E Viewer options Fog Visibilty Simple transparency AntiAliasing TIP Turning off items speeds up and simplifies the display of complex mechanisms and provides a useful way to limit selection to specific items 2 24 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 7 Visualiz
282. he Control Editor is a workspace for configuration of the control system The graphical representation is a block based diagram that consists of a series of control blocks that can be connected to simulate your control system This editing environment allows you to create and manipulate the control system using drag and drop functionality It also features grid and snapping tools see Section 5 4 1 Setting Grid and Snap To open the Control Editor click the Show Control Editor button on the eo Windows toolbar or Windows menu The Control Editor displays the control system an example is shown below See Chapter 5 Control System Modeling for more information about control systems 2 14 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 5 Touring the interface Control Editor FEF NOTE The Control Editor is empty until you create control elements Graph Views The graph windows can display various views of your results You can customize graphs of selected simulation results and manipulate the view in the graph window To open a graph window right click the graph from m the Model Manager Results list and select Show Graph Graph Views are displayed in the Workspace area as shown below zi Tractor rear linkage Acceleration Forces FEE Tractor rear linkage Forces uA PA VV il 0 0 5 1 15 physical time 150 mis 2 eo D 0 5 1 physical time 400 Fedem Release 5 0 User s Guide 2 1
283. he Speed setting if necessary Continuous this option allows you to play the animation repeatedly until you click the Stop Play button Cycle enables playing the animation in Forward Play mode until it reaches the end then plays it in Reverse Play mode 9 Close button closes the Play Panel and ends the animation session NOTE The Play Panel does not appear if the animation consists of a single frame e g Time Summary animations with results from a Strain Coat Recovery To close such animations you have to select End Animation Session from the Results menu or type Ctrl X Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 4 Viewing animations 7 4 3 Animation controls Once an animation is loaded you can open N Animation Control Oy x the Animation Control panel by selecting amera Show Animation Controls on the Tools z eference Link None menu The Animation Control panel is en e otion displayed as shown to the right Changes o A made to settings in this panel are instantaneously applied to the animation ore me M Show Link Deformation 0 Camera enables selection of Scale 3 00 reference link for the camera Contour Legend movement See also Camera reference IV Show Contour link below IV Show Legend j i igi s ull color X Motion enables display of rigid body cak E icol motion of the mechanism Mapping liner 5 el
284. he graph or graphs you want to export in the Model Manager Results list right click and select Export gt Export Graphs A file 16 Lood impor dialog will pop up with slightly different appearance depending on Sort by Name Eee Sees what you have selected oe Dd If you have selected one Sei graph ora collection of Look in C Software_Testing 03_BigModels Loader Input_Files v curves belonging to the a same graph the file dialog will let you select directory file name and format for the exported graph file If you selected only a subset of curves from a graph only Deom the selected curves will be MEUM EE a pea written to the graph file File format Multi Column ASCII File Export to a single file File name Joraph_export If you have selected several graphs and or curves belonging to different graphs the file dialog will let you specify a directory to write the files to and the file format It also gives you the option to write the entire selection to a single file In that case you may also specify a file name Fedem Release 5 0 User s Guide 7 19 7 Postprocessing Results 7 2 Graphs Sass CAUTION When exporting graphs all curves in the selection must have equal x axis definitions both in terms of number of data points and increment Ax When exporting to Multi Column ASCII the x axis values of the exported graph are thus set identical to those o
285. he input is less than or equal to the lower limit the output is the input minus the lower limit Hysteresis block The Hysteresis backlash block controls output in such a way that a change in input causes an equal change in the output However changes in direction of the input signal have no effect on the output The amount of side to side play in the system is referred to as the deadband The deadband is centered about the output PI PD and PID controllers PI PD and PID controllers are used to control output in such a way that the given input source forces a desired result Pl PD and PID controllers are described in detail in the Fedem R5 0 Theory Guide Section 8 4 4 Compensator elements The following are controllers used in Fedem PID Controller block PI Controller block PD Controller block P Limited block limited PI controller Fedem Release 5 0 User s Guide 5 Control System Modeling 5 4 Building control modules P Limited D block limited PD controller Pl Limited D block limited PID controller in serial form P Limited and D block limited controller in serial form 5 3 7 General transfer functions General transfer functions are continuous mathematical functions used to describe differential equations The time response of the system is characterized by poles the roots of the functions Fedem uses the general transfer functions described in the following paragraphs Fo
286. he local XY plane ISWTCH n directly specify the value of the ISWTCH parameter in the DTYRE call see STI documentation Radial stiffness and damping coefficients of the tire may be specified through ZradialStiff lt k gt radialDamp c These parameters will be added to the system Newton matrix of the mechanism They do not affect the tire models internally Fedem Release 5 0 User s Guide F 7 F Beta feature documentation F 6 Roads F 6 F 7 Roads The following commands can be entered in the description field of a Road to apply a time dependent translation of the road surface applicable for the MF Tyre and SWIFT tire models only RoadXengId id RoadYengId id RoadZengId id where lt id gt is the base ID of the Function defining the time dependent road translation in the indicated global coordinate direction NOTE The base ID of a mechanism object is normally not visible in the Fedem UI To see the base ID you have to launch Fedem in debug mode using command line option debug Then the base ID appears in curly braces in the Object Browser Additional masses The additional masses are scaled using a Function when the command MassScaleEngine id is entered in the description field for the selected Triad The id is the function s base ID The additional rotational inertias for the selected triad are also scaled using the same function NOTE The base ID of a mechanism obj
287. he model results database in the 1ink_DB directory This link repository will follow the model and be copied along with the results if saving the model as a new name External link repository Sometimes it is useful to be able to share and reuse the link repository among several model files Using an external link repository enables such sharing If this is set using Save As will not copy the link repository but the original and the new model will point to the same link repository and thus share any identical information External single link repository It is possible to use a specific link repository for an individual link This is used to import and reuse a link from an existing link repository Setting the model link repository The model link repository can be set in the Model Preferences dialog Edit gt Model Preferences Below is a portion of the dialog shown l A Model link repository intemal amp b Change Switch to external repository e The position of the current model link repository This button switches between internal and external repository The Change button changes the external repository to a new directory This might be an empty directory or a directory used as link repository by another model When changing the repository Fedem will copy the active content of the current link repository to the new destination prompting on wether to overwrite if necessary The old repository wi
288. he overall maximum of the y values in the curve data set Q Min The overall minimum of the y values in the curve data set Calculate button Press this button to retrieve the statistical values Q Use scaled shifted Toggling on this button will make the calculation take into account any scale and shift values defined in the Scale and Shift tab see Section 7 2 7 Scale and Shift and in effect do the calculations on the curve as it is shown in the graph view If the button is toggled off the unprocessed data will be used X Axis Domain Toggle the Entire button on to use all the data points on the curve or specify a start and a stop value If you specify an interval two vertical lines at the start and stop values will appear in the graph view when you click the Calculate button 7 2 10 Fatigue calculation from standard S N curves Options to assess fatigue results based on plotted stress histories are found in the Fatigue tab of the Property Editor panel This tab is visible only when fatigue calculation is applicable which means that the curve must be plotting a stress quantity computed by the Strain Gage Recovery module vs Physical Time The stress quantity can either be Gage stress from a Strain rosette or the Signed Abs Max value from the Stress tensor in a Strain rosette Fatigue calculation is also applicable for curves loaded from file when the Enable Fatigue toggle is enabled The Fatigue tab is shown below Here
289. he simulation is aborted vou can enable a Restart simulation if you already have some simulation results and specify the Restart time defining the time step to restart from If the specified time does not match an existing time step the closest step after the specified time is used NOTE In a restart simulation you are allowed to adjust any of the other Solver Setup parameters and options as well as adjusting the additional solver options for the Dynamics solver see Section 6 2 3 Additional solver options However you can not change any properties of the mechanism model itself Restarting a Dynamics simulation is very handy if you discover you need to continue a simulation that was terminated abnormally or you just want a longer event than was originally defined You may restart a simulation as many times you wish Each restart adds a new set of result files to the existing results database such that subsequent post processing and recovery runs can be conducted over the overall time domain spanned by both the initial run and the restart s If the time domain of the individual runs overlap only 6 the latest produced results will be used in post processing and recovery See Section 8 2 3 Result files from restart simulations for more information on the management of results from restart simulations Fedem Release 5 0 User s Guide 6 19 6 Mechanism Analysis 6 5 Dynamics analysis a Integration tab You can optim
290. he tire which involve often important secondary effects In Figure A 1 these factors have been brought in matrix form A distinction has been made between quasi steady state and vibratory behavior and besides between in plane and out of plane aspects The primary task factors are shaded in green The remaining secondary factors are not shaded The requirements to transmit forces in the three perpendicular directions Fx Fy and Fz and to cushion the vehicle against road irregularities involve secondary factors like radial lateral and longitudinal distortions and slip Although considered as secondary factors some of the quantities involved have to be treated as input variables into the system which generate the forces Figure A 2 presents the input and output vectors In this diagram the tire is assumed to be uniform and to move over a flat road surface The input vector results from motions of the wheel relative to the road It is advantageous to recognize the fact that for small Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 4 Axis Systems and Definitions deviations from the straight ahead motion in plane and out of plane motions of the assumedly symmetric wheel tire system are uncoupled The forces and moments are considered as output quantities of the tire model They are assumed to act on a rigid disc with inertial properties equal to those of the undeflected tire The forces may differ from the correspon
291. hift 4 54 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions This function interpolates linearly between the user specified points xj The interpolated ordinate value is then scaled by a factor s and shifted by k The vertical shift value kis set to the scalar entered in the Additional shift field If Shift function to zero out start value is checked as well the start value x is also subtracted so that k x x4 For abscissa values outside the function domain an extrapolated ordinate is assigned such that vy x 2 f v 7 f x and v x 2 f v f x Spline Xin Viv ie Pl n y A third order spline approximation is F po calculated from a set of user specified L x points x y which may be entered in Gy L Gy ys the same way as for Polyline functions NU few At least 4 points are required Qxo y2 N Qn 1Yn 1 __ __1_ __ __ __ j Referto Section 4 10 4 Extrapolation X to learn about the extrapolation of a Spline function TIP If you have a Polyline function consisting of at least four points you can change its type into Spline without loosing the entered curve point data This is useful just to see how the same set of points appear when they are interpolated with a cubic spline basis instead of the piece wise linear interpolation You can then change back to Polyline again if you want to retain the linear interpolation in the simulation Math Expression The math expr
292. i Model Manager and select Result Tie anii selector A dialog will pop up shown to z Joints Revolute joints the right io E i i Rz joint variables igular velocity io Angular acceleration Rz spring variables i 2 Select the result you want to plot and drag it from the Result Selector and onto the Result list of the Model Manager If Ei you drop it on an existing graph it will eu be created as a curve in that graph iae otherwise a new graph will be created ji 7 8 with the selected results as a new curve 9 i 10 Triads Links Axial springs Loads i If the graph receiving the new curve is visible the new data is automatically loaded and displayed Strain rosettes Engines Mechanisms For more detailed information about the Result Selector see Selecting RDB results in Section 7 2 5 Possible Results Repeat a curve definition for every object in the model In some cases it is useful to look at some particular result from all the objects of a certain type in the model E g to find the triad with the highest forces in the model or to look at the acceleration levels all over the model This can be achieved in a convenient way using the command labeled Repeat curve for all objects This command is available in the right click menu of the Result list of the Model Manager when right clicking a curve This command repeats the curve definition
293. iables listed in the Possible Results list may not be present in the results database For example a joint may or may not have a spring or damper attached at each DOF but in the Possible Results list all possible springs and dampers are listed one for each joint DOF If such a nonexistent variable is selected the associated curve does not appear in the graph view NOTE Variables such as Physical Time and Time Step Number are not associated with a mechanism element and are listed independently in both lists NOTE Categories such as Revolute Joints or Z Rotation Joint Variables cannot be selected as variables only those items in the expanded lists such as Angular Deflection can be selected for use as variables 5 Repeat steps 2 through 4 to select the Y Axis variable Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs NENNEN TIP To easily find out what result quantities if any that already have been plotted for a given mechanism object just select the object and inspect the Topology panel see Section 2 5 4 ID and Topology panel The curves plotting quantities in the selected object are then listed under the Plotted by heading Derived angular quantities from position matrices Totally 10 derived quantities may be plotted for a Position Euler Ange ZY x matrix result item as shown to the right The EulerAngle Eason quantities top three are the indicated angles computed Position Length
294. id this restriction When the function key is released the manipulation stops CAUTION When pressing the left mouse button while using the function keys Fedem grabs the mouse and keyboard control Pan F1 The Pan command shifts the view left right up or down Zoom F2 The Zoom LS command moves the scene closer or further away from the camera It pays attention to the rotation center and will zoom towards it see Select Rotation Center F4 Select below This is useful when you need to examine an object or its components closely TIP To achieve maximum zoom at a specific point select the point using Select Rotation Center F4 and then zoom in on the point using Zoom F2 Rotate F3 The Rotate 4p command enables you to dynamically rotate your model around a point or an axis at the rotation center see Select Rotation Center F4 Select below The rotation can be performed in two different ways depending on the position of the cursor when you press F3 9 Axis rotation With the cursor near the edge of the Modeler window the view rotates around an axis that is perpendicular to the screen Point Rotation With the cursor near the center of the window the view rotates around a point located at the rotation center of the Modeler some distance into the model This allows rotation of the view in any direction around the point TIP The rotation motion is sensitive to the speed of the mouse If the mouse i
295. ie zZ Rot Deg RotY Deg RotZ Deg 00 0 0 0 0 Joo 00 00 Reduction Options tab The settings on the Reduction Options tab affect how the link is reduced Part Origin Reduction Options Advanced Singularity criterion 1e 012 Eigenvalue Factorization Q Needs reduction Component modes 0 e Ma 3 Stiffness Eigenvalue tolerance 1e 008 L Consistent mass matrix 4 Recovery matrix storage precision C Sindi m Ignore check sum test aes eee Double precision Expand mode shapes O Singularity criterion This is the tolerance used to decide whether the the stiffness and mass matrices are singular when they are factorized during model reduction See Singularity tolerance in Section 6 3 4 Fedem Release 5 0 User s Guide 4 9 4 Mechanism Elements 4 1 Links Component modes Allows you to specify the number of component modes representing the internal eliminated nodal degrees of freedom after CMS model reduction See Section 6 3 2 Using component modes Eigenvalue tolerance This is the maximum acceptable relative error in the computed eigenvalues in the fixed boundary eigenvalue analysis Consistent mass matrix Enables the use of consistent mass matrix in the model reduction process If disabled a lumped mass matrix approach is used See Section 6 3 3 Using lumped mass matrix Ignore check sum test Disables the check on whether the reduced
296. ies This group of options controls how the deflection is evaluated to produce the spring force or torque The spring can be either a linear spring with a constant stiffness or a non linear spring with a non linear relationship between the deflection and the force torque or the stiffness The spring force torque is reckoned to be positive when it is working in the opposite direction of the increasing spring length angle In this field you can enter a constant spring stiffness or select a defined spring characteristic from the pull down menu Q scale The spring force or torque can be scaled by a function This can for instance be used to switch the spring on and off during the simulation When no function is selected the scale is set to 1 0 Damper properties This group of options controls the evaluation of C a damper s force or torque from its velocity joo Q 1 Both linear and non linear dampers are allowed Scale None a A linear damper uses a constant damping I Use deformational velocity coefficient A non linear one uses a function to control how the damper force or coefficient depends on its velocity In this field a constant damping coefficient can be entered or you can select a damper characteristic from the pull down menu scale The damper force or torque can be scaled by a function This can for instance be used to switch the damper on and off during the simulation When no function is selected the scale
297. iewing 2 7 modes postprocessing 6 34 modified Newton Raphson iteration 6 20 motion constraints 2 8 3 10 mouse using 2 17 Mouse button 4 47 movability 3 4 3 6 movabity 3 2 move curves 7 6 MSC Patran 1 4 MSC Nastran Bulk Data File bd format 1 4 multibody systems applications 1 3 multiple face results 7 27 Fedem Release 5 0 User s Guide multiplier block 5 4 Output List attachment process 3 16 N window 2 16 opening 2 16 nas format 2 4 C 1 Nastran Bulk Data nas or bdf format C 1 P navigating 2 13 pan F1 2 20 nCode DAC dac format 2 35 pan down 2 24 Negative pivots 6 14 pan left 2 24 Newmark time integration 6 2 pan right 2 24 Newton integration algorithm 6 18 pan up 2 24 Newton Raphson equilibrium panels iterations 6 2 hiding 2 14 nodal parallel projection 2 23 attributes 1 5 Parameters coordinates 1 5 for SWIFT Tyre B 22 nodes perform 1 5 syntax for C 3 perspective view 2 23 nonlinear equations PI PD and PID controllers 5 6 solution of 6 20 PID control block 5 9 Normal load pin joints 4 26 and contact point C for MF Tyre A 7 Play Panel 7 33 Notation for SWIFT Tyre B 3 point rotation 2 21 point force vectors 4 46 o point to path joints 4 30 4 32 point to point joints 4 27 object movability polygons item appearance 2 27 determining 3 10 postprocessing object selection 2 17 animating options 7 2 confirming 2 19 capabilities 1 2 ground 2 19 d
298. ile output The DAC and ASCII file output is not affected 6 8 4 Strain rosette definition file format It is possible to define strain rosettes in an ASCII input file as shown in the example below and read them into fedem id type link numNodes n1 n2 n3 n4 zPos Xx Xy Xz Zx Zy Zz E mod nu 10 2 1 4 844 846 830 828 0 0 0 0 1 0 0 0 0 0 0 0 1 0 2 06e 11 0 0 20 4 1 3 845 846 828 0 01 0 0 1 0 0 0 0 0 0 0 1 0 2 06e 11 0 0 end Each line defines a strain rosette where the following data must be given id The id number is used for naming purposes of the result files The above example defines two strain rosettes with identifiers 10 and 20 respectively 6 38 Fedem Release 5 0 User s Guide 6 Mechanism Analysis p M 6 8 Strain rosette analysis type According to the figure below rosette 10 is of type 2 i e a two gages with 90 degrees between the gages whereas rosette 20 is of type 3 three gages with 60 degrees between the gages i ie iz 3 i 2 is 2 15 ck Type 1 Type 2 Type 3 Type 4 Single gage Double gage 90 angle Triple gage 60 angle Triple gage 45 angle i link The super element link number that the present rosette is attached to numNodes n1 n2 n3 n4 Number of nodes for the element followed by node numbers that define the element topology Permissible values for numNodes are 3 and 4 giving CST triangle and bi linear quad element respectively The nodal numbers must be given in a
299. ile specified in Dynamics Solver Setup See Output tab in Section 6 5 1 Fourier Analysis tab allows you to perform a Fast Fourier Transformation of the curve data See Section 7 2 6 Fourier analysis Scale and Shift tab allows you to apply scaling and shift to the curve data See Section 7 2 7 Scale and Shift Appearance tab allows you to change appearance of individual curves See Section 7 2 8 Appearance Curve Statistics tab allows you to extract statistical properties for individual curves See Section 7 2 9 Curve Statistics e e 8 Fatigue tab allows you to assess fatigue properties based on the curve data See Section 7 2 10 Fatigue calculation from standard S N curves NOTE The curve is not displayed in the graph view until you have fully defined the curve variables indicated by the word Complete appearing at the bottom of the Property Editor panel The word Incomplete appears at the same location until the curve is properly defined TIP Once you have created and fully defined curves you can select them directly in the graph view window or clicking a curve in the Legend When selected curves are highlighted in red F TIP You can drag a curve from one graph and drop into another in the Model Manager Results List Fedem Release 5 0 User s Guide 7 9 7 Postprocessing Results 7 10 7 2 Graphs Selecting RDB results To select the results to plot as x and y coo
300. iles Secondly FE Fatigueisrun in batch mode to create a summary for the link in each event Thirdly fefcom is run to sum up the damages from each event Lastly fef2frs is run to create a Fedem Results File This procedure is repeated for all links NOTE All Duty Cycle calculations are performed in a temporary sub directory named TempDir fedem lt gt where lt TempDir gt is the temporary directory defined as explained in Section 6 2 Controlling placement of temporary files However if the name lt TempDir gt is longer than 120 characters or contain spaces or on UNIX upper case letters then C V Temp on Windows or tmp on UNIX is used instead If the Duty Cycle calculation completes successfully the temporary sub directory is deleted However if the calculation fails the directory is retained such that you may check for any hints to why the calculation failed in that directory 6 46 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 11 Interaction during processing 6 10 5 Viewing Duty Cycle results When Duty Cycle analysis has completed you may create a Time Summary animation to view the results The available results are Damage Log Damage Life and Log Life See Section 7 3 1 Managing animations for details on how to set up animations 6 11 Interaction during processing 6 11 1 Simultaneous viewing and processing If you already have set up graphs and animations see Chapter 7 Postpr
301. imation Session Ctrl x Workspace area 5 Show Animation Controls The Workspace area is used to display 9 Result File Browser each of the graphs and animations you AES Cs create Jj Delete Results VW Delete Stress recovery results P Delete Mode Shape recovery results Be Delete Strain Rosette results Graphs can be displayed in individual windows that are labeled with the e Delete Strain Coat Recovery Summary results user specified description of the b Deis Duty graph these windows are called graph views To specify a description and display a graph window see Section 7 2 4 Graph properties and Section 7 2 3 Showing a graph 7 2 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs a Animations can be displayed in the Modeler window one at a time To display an animation see Loading animations in Section 7 3 1 7 2 Graphs To track the progress of any variable during the simulation you can create two dimensional graphs of the values Each graph can contain several curves enabling comparison of the simulation variables You can customize your graphs with titles axis and data labels and legends as shown below Cylinder Force Cylinder Force Force Values 100000 50000 50000 Force H 100000 150000 200000 250000 T T T T T T T T T T T D 1 2 3 4 5 Time s X Physicaltime Y Axial spring 2 Force value
302. in Reduction Options Advanced FE Part Finite Element Mod eo Generic Part Repository entry internal C Documents and SettingsNjacob untitled 2 RDBNink 1 Change Needs o Visualization only Imported file O JCB LastSyntese Parts tipping_lever2 bdf No unit conversion reduction Structural E 5 r Scaling of Dynamic Propet Mass proportional foo Stiffness 1 0 Mass 0 Stiffness proportional fo 005 Part Origin CoG Mass Stiffness Advanced FE Part Visualization Generic Part File Change Visualization only Using FE model as visualization Structural Damping Ge Sealing of Dynamic Properties Mass proportional no Stiffness ho ooo Stiffness proportional nns Mass f0 oo Part Origin FE Part Finite Element Mode C Generic Part Repository entry internal C Documents and Settings jacob untitled_2_RDB ink_ Change e Visualization only Imported file O JCB LastSyntese Parts tipping_lever2 bdf No unit conversion Link is ignored in solvers Triads will be attached to ground FE Part Generic Part Link type selector You can switch between the FE model or the Generic Part model at any time during modeling NOTE When switching between FE Part and Generic Part Fedem tries to use the supplied FE data and visualization data in a sensible way If your Link is defined as an FE Part and you switch to Generic Part the FE model
303. in the results menu The mode shape recovery results can be deleted by clicking the Delete Mode shape recovery button on in the results menu The strain rosette recovery results can be deleted by clicking the Delete Strain Rosette results button on in the results menu The strain coat recovery results can be deleted by clicking the Delete Strain Coat Recovery Summary results button on in the results menu The duty cycle recovery results can be deleted by clicking the Delete Duty Cycle Recovery results button on in the results menu 5 m Gk X X NOTE The results files are deleted immediately when performing these actions 6 48 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 13 Automated curve export from multiple result database cy 6 13 Automated curve export from multiple result database files If you need to export curve data from several result database files into a single output file e 9 if you want curves from one or more Strain Rosette analyses exported to a single RPC file that can be done by executing the Fedem Curve Export Utility module after the necessary solver tasks have been completed This module can only be invoked as a separate command from a terminal window or command prompt Start the curve export by issuing the following command fedem graphexp frsFile fnames modelFile mname curvePlotFile cname options where fnames is a list of one or more frs files on the form fileli fil
304. in the spring Empty if no scaling is done Damper Damper characteristic Either a number describing a constant coefficient of the damper or a description of a function used as a non linear coefficient or force velocity relationship D Deformational velocity A label indicating whether the damper is using deformational velocity d if on empty if not Dmp scale The description of the function that is used to scale the force developed in the damper Empty if no scaling is specified Advanced joint properties For the Ball joint and Free joint you have possibility to alter the numerical formulation of how the rotational DOFs are represented internally You can also control the spring inter connectivity a feature that can be used to describe the circular or cylindrical stiffness behavior of rubber bushings etc This is done through the Advanced tab shown below Fedem Release 5 0 User s Guide 4 25 4 Mechanism Elements 4 26 4 4 Joints Summary Origin Tx Ty Tz Rx Ry Rz Advanced Rotation formulation Spring inter connectivity ormulation Sequential rotation Follower axis xj Translation None x Sequence zvx 1 Rotation None M Qu of 90 degrees about Y axis gives a singularity You may change the rotational formulation of the joint The following choices are available Sequential rotation Follower axis Euler angle parametrization Sequential rotation Orthogonal
305. indicates that the results are recognized as OK a red cross indicates failure or that the link hasn t yet been reduced Dynamics Shows the result files produced by the Dynamics Solver Recovery Displays a list of all the links in your model and for each link the result files for that link grouped by the recovery process they were created by NOTE If you are working on a slow machine and have a lot of results displayed in the file list continuously updating the list may steal valuable CPU cycles from the solver process Close the dialog to disable these updates The Info view When selecting a file in the file list the file can be viewed in the info view The plain text files fco fop fao fsi and res are displayed as is while selecting an rs file will show only the top of the header section Selecting a link under Reduction will show information about that link Result File Browser Loader saveAS1 f mm s ni xj File Last modified S Reduction i W Front 0001 i m WI 2 Boom 0001 File Info Imported FE file D Fedem Fedem Models Loader Input_Files Bucket flm Repository file D Fedem Fedem Models Loader Input_Files Loader_savei Number of DOFs 5022 me Number of nodes 837 MEE 3 Bucket 0001 Number of elements 1481 i 4 BellCrank D001 BEAM2 6 MIS BucketLink 0001 mnm 1368 H E Dynamics H E Recovery Number of 6 DOF Triads 15 Close Fedem Release
306. indric joint 4 32 cylindrical motion 3 11 D dac format 2 35 dampers properties 4 41 dead zone block 5 6 lower and upper limits 5 6 output 5 6 Definitions listed for MF Tyre A 38 degrees of freedom DOFs 4 52 delay block 5 5 delete all stickers 3 7 selecting multiple items 2 18 deleting stickers and recreating 3 7 derivator block 5 5 description field commands F 1 deselecting items in the Model Manager 2 9 detach 3 21 DOFs 4 20 4 52 See also degrees of freedom duty cycle analysis 6 44 license 6 45 dynamic functions 2 19 2 20 pan F1 command 2 20 rotate F3 command 2 21 select dynamic center F4 command 2 21 viewing 2 19 zoom F2 command 2 20 dynamic zooming and rotation 2 21 dynamics analysis about 6 2 controlling parameters 6 18 Fedem Release 5 0 User s Guide performing 6 2 unbalanced forces 6 3 dynamics simulation 8 9 before beginning 6 2 deleting result files 6 48 result files 8 9 starting 6 30 Dynamics Solver E option files 8 9 setup 6 18 6 30 eigenmode specify shift factor 6 23 Eigenmode animations 7 24 eigenmode solutions 1 2 calculating 6 23 computed by Fedem 6 3 eigenmodes calculating 6 3 damped 6 23 options 7 28 specify number to be computed 6 23 element expressions syntax C 5 properties 1 5 topologies 1 5 Element group properties 4 17 element groups creation 4 5 4 16 other identifiers C 12
307. ine Width parameter set for the Mechanism symbols See Section 2 7 4 General Appearance 28 Opening and saving model files B 2 8 4 Opening a file You can open a Fedem model file created in this version or any of the previous versions of Fedem through the following steps 1 Chose Open in the File menu You can also use the file open icon in the toolbar 2 Locate the Fedem model you want to open and click Open xi Look in E d FedemModels lt a mg a O MyFedemModel RDB O Tire _RDB ia MyFedemModel fmm B Tire fmm m File name MyFedemMadel fmm File type Fedem model file fmm Cancel Skip FE Data Ignore FE Data Settings The model file selection dialog normally displays all files with the Fedem model file extension mm However you may open a file with any extension by selecting the All files filter in the File type pull down CAUTION If you choose to open a file without the fmm extension you should make sure itis a proper Fedem model file Attempting to open a non model file will usually result in an empty model but unpredictable behavior may also occur depending on the actual contents of the file Fedem Release 5 0 User s Guide 2 29 2 Learning the Basics 2 8 Opening and saving model files 2 30 In the file selection dialog you can skip the loading of FE data for the links See also Section 2 9 2 Skipping FE Data when opening a model file If the op
308. ing Fedem also tracks what files are part of your modified and unsaved model and can thus tell which files belong to the saved and the unsaved modified version of your model 8 1 1 Discarding unsaved changes When you open an existing model the original result files present on disk are preserved even if you delete results change the model run the solvers etc as long as you do not save your model If you exit without saving all the original data remains unchanged and the result database will be restored to the state of the last save The initial data is deleted or overwritten only when the model is saved Consequently to be sure that the result files known by Fedem are those and only those present on disk the model has to be saved first NOTE If you use the Result File Browser to delete result files they will be physically removed from disc instantly Their removal will not be delayed until the first save This is done to actually free disk space as you delete the files and not when you save your model 8 1 2 Saving a model When the model is saved the model file is updated with the current information from memory including information on the contents and status of the results directory In addition all changed links are saved in the link repository default 12nk DB directory and the obsolete files in the results database are deleted 8 2 Fedem Release 5 0 User s Guide 8 Managing Results 8 2 Result File Browser
309. ing network for the pneumatic trail SWIFT is suitable for path curvature with a wavelength in the order of two times the contact length For braking traction applications wavelengths as small as half the contact length are well described The transient slip behavior is well described up to full sliding due to modelling of decrease in relaxation length for increased slip levels Road Input The dynamic model has been validated for load variations up to 100 Hz and the slip model for wavelengths as small as two times the contact length SWIFT uses a single point contact model which generally can be B Using the SWIFT Tyre Model B 2 Notation iy applied as long as the road curvature is about half of the tire curvature To be able to cope with shorter obstacles a method of describing enveloping behavior is applied It is assumed that a measured road profile can be evaluated as a series of step obstacles for which the enveloping effect of the tire is described with so called basic functions This method has been validated for isolated obstacles up to 10 of the tire radius and provides an accurate prediction of vertical load longitudinal force and wheel rotation fluctuations Also with measured road profiles good correlation has been found with vehicle measurement data B 1 4 References 1 Zegelaar P W A The Dynamic Response of Tyres to Brake Torque Variations and Road Unevenesses PhD Thesis Delft University of Technology The Nethe
310. ing structural FE element Strain Coat Properties The property fields that are referred to by the strain coat element fields have the following syntax PSTRC pid name PMAT mid PTHICKREF tid I PHEIGHT hid Parameter Value Type Description pid Integer Strain coat property identifier name String Result set name to be displayed in the animation UI one of Top Bottom or Basic mid Integer Reference to a material property field Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format C 1 8 Parameter Value Type Description tid Integer Reference to a thickness relative z position field hid Integer Reference to an absolute z position field PTHICKREF tid fact PTHICK gid Parameter Value Type Description tid Integer z position identifier fact Real Location of the calculation point in the thickness direction of a shell as a fraction of the referenced shell thickness i e the z position is z fact t where t is the thickness referenced through the parameter gid gid Integer Reference to a thickness field PHEIGHT hid h Parameter Value Type Description hid Integer Z h Real Absolute location of the calculation point in the thickness direction of a shell i e the z position is z h Other identifiers The following identifiers are used to define element groups GROUP id el
311. ing the model Color Allows editing of the fF Joints E RGB settings for each item type Press the Edit button pod Jes next to an item type to edit the Green oss default display color for that Bue p item In the item window shown at right move the OK Cancel sliders to change the settings or enter the desired values directly in the number fields Size Size is a scale factor for sizing the display of mechanism entities To change the size of items enter a new number in the size field symbol lines together with all 1D elements and Surface Connectors in the FE parts see Section 3 6 2 Surface Connectors To change the line width move the slider right or left Line Width This is a scale factor for the line width of all mechanism E Default colors This area enables the user to edit the colors used on the modeling background and unattached mechanism items It also allows you to set the colors on triads that are attached to the ground to distinguish them from triads that are free to move The default colors may be changed in a similar ways as changing the colors for Mechanism symbols Viewer options This area enables the user to modify the way that models are rendered 9 Fog is an option that enables you to create a fog like effect around your model that appears as fog or darkness or even an underwater scene The distant parts of the model appear to fade into the backgr
312. irec tions of the bushing element Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format PBUSHECCENT beid ex ey ez Parameter Value Type Description beid Integer Eccentricity vector identifier ex ey ez Real Offset vector from local node 1 to the bushing element location PORIENT oid ox oy oz Parameter Value Type Description oid Integer Orientation vector identifier ox oy oz Real Local z axis of the element PCOORDSYS csid ox oy OZ zx zy ZZ px py pz Parameter Value Type Description csid Integer Local coordinate system identifier ox oy oz Real Origin of the local coordinate system zx zy zz Real Local Z axis in the coordinate system px py pz Real Point in the local XZ plane PSPRING sid k11 k21 k22 k31 k32 k33 k41 k42 k43 k44 k51 k52 k53 k54 k55 k61 k62 k63 k64 k65 k66 type Parameter Value Type Description sid Integer Spring stiffness matrix identifier kij Real Component i j of the symmetric 6x6 spring stiffness matrix type Integer Spring type flag 1 Translatory spring 2 Rotational spring Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format es PMASS mid I11 I21 I22 131 132 133 141 142 143 144 251 152 I53 2354 I55 I61 I62 163 164 I65 I66j Parameter Value Type Description mid Integer Mass property identifier
313. irectories is created under the 1ink DB directory to store information about already reduced links This directory is named linkname _ where linkname is the name of the actual link and represents a configuration number Option files for Fedem Reducer are also stored in the linkname _ directories This enables reduced links to be moved between result databases NOTE When link specific or model specific repository is used see Section 4 1 5 Using link repositories the file name conventions apply to the subdirectories of that directory and not the 1ink DB directory CAUTION If you use a file browser to remove unwanted files in the Fedem Results Database directory structure do not remove the f t1 files directly under the link DB directory Other files will be automatically recreated when a new simulation starts CAUTION If you use a file browser to move a Fedem Mechanism Model file mm you must also move the 1ink_DB directory to ensure inclusion of the link definitions Model reduction file management BH When Link Reduction is started a new directory for each link is created and the files needed by fedem_reducer are written to this directory These files include an t1 file with external node specification and the options files fco fop and fao see Appendix D 1 File types After the reduction all input files are retained for reference and a possible rerun of the process in batch mod
314. is depicted in the Modeler as shown to the right Performing a Smart Move To move an object or group of objects using the Smart Move command complete the following steps 1 Click the Smart Move button from the Mechanism Tools toolbar The Guide bar prompts you to select objects to move 2 Toselect an object and indicate the from point place the cursor over a point on the object and press the left mouse button The selection snaps to the nearest node or point on the object This point becomes the from point and a symbol is shown that depicts the movability of the current selection TIP Several objects can be selected by pressing and holding the Ctrl key while selecting objects To change the last selected object only release the Ctrl key and select until you hit the right object To remove several of the last selected objects from the selection release the Ctrl key and press the left mouse button on some empty space in the modeler until all the objects in question is deselected TIP You can also type in a discrete point or edit the point using the Interactive Odometer see Section 3 3 2 Interactive Odometer and 3D Point Marker 3 When you are satisfied with the object and the from point selected press Done to confirm it The Guide bar then prompts for you to select a to point Fedem Release 5 0 User s Guide 3 11 3 Mechanism Modeling 3 5 Moving mechanism elements 4 Select the to point in the same way you selecte
315. is set to 1 0 NOTE In Fedem version 2 5m3 or lower non linear dampers were modeled using a function to change the damper coefficient When opening such models in version 3 0 or higher those dampers are converted by setting the damper functions as scale functions and the coefficient to 1 0 Use deformational velocity This option is available only if the damper is acting together with a spring with a forced change in its stress free Fedem Release 5 0 User s Guide 4 41 4 Mechanism Elements 4 7 Springs and Dampers length The option enables the usage of the deformational velocity of the connected spring when evaluating the damper The deformational velocity is the spring velocity without the velocity component coming from a forced change in the stress free length NOTE The Use deformational velocity toggle is not visible for axial dampers unless there is a parallel axial spring connected to the same triads 4 7 3 Axial spring symbol The symbol for an axial spring is displayed in the Modeler as shown to the right First triad axial spring second triad 4 7 4 Axial damper symbol The symbol for an axial damper 4 is displayed in the Modeler as e qg iz d shown to the right FIN i amp f lt O First triad c9 axial damper f second triad 4 7 5 Spring and damper characteristics Non linear springs and dampers are defined by creating a spring or damper character
316. is should be interpreted as follows Error A problem has occurred that makes it impossible or undesirable to continue the simulation The simulation is aborted in a controlled manner Warning A problem has occurred that may affect the simulation results although the simulation itself continues However one should be more critical to obtained results when warnings occur and consider changing the model Note The event causing this kind of message is usually of no significance for the results The message informs the user that an action has been made to perform a specific task etc When a simulation process aborts with Error messages you will also see the message See filename res for further details That means that sometimes but not always there are further error messages on the res file explaining the problem Note however that these additional messages are often of a low level character and harder to understand for the average user The main rule is that messages printed to the Output List window should be sufficient to understand the scope of the problem A solver error will often create several messages on the res file all relating to the same problem incident This typically happens if an exception or error occurs deep inside a program module and from there prints an error message on what is wrong basing the message on the knowledge available to that module As the program trace back unfolds more messages on the
317. istics and selecting them in the spring or damper property panel There are four basic types of characteristics available both for springs and dampers The differences between them are whether they define a rotational or translational spring damper behavior and whether they define a stiffness damping coefficient curve or a force torque curve In addition there are two types of advanced spring characteristics available for translational and rotational springs respectively see Section 4 7 6 Advanced spring characteristics Spring characteristics The four basic spring characteristics types are 4 42 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 7 Springs and Dampers Force Translation Torque Rotation Stiffness Translation gt Stiffness Rotation Force Translation Torque Translation These characteristics describe the relationship between displacement and spring force torque directly The spring stiffness is then computed as the derivative of the provided curve ra D Stiffness Translation Stiffness Rotation These characteristics describe the relationship between the displacement and the spring stiffness directly The spring force torque is then computed as the integral of the provided curve from 0 to the current deflection A F kGod 0 The definition of the curves used can be done using one of the following function shape types see Section 4 10 5 Function Types Po
318. ists of all elements referring to one particular material PMAT or thickness PTHICK property record in the FE model file The ID numbers of these groups correspond to the ID numbers of the associated property record Implicit groups are created only for property records that are in use NOTE When the imported FE model file is a Nastran bulk data file the created PMAT and PTHICK groups correspond to the MAT1 and PSHELL bulk entries respectively with corresponding ID numbers No implicit groups are created for PSOLID bulk entries The element groups are visible in Objects list of the Model Manager panel under each link node as shown to the right They can be used to control component appearance see Section 2 7 Visualizing the model calculation focus see Section 6 2 Link and group wise solving Function definitions Joints f Links H 1 Front 2 Boom 3 Bucket 1 PTHICK ap 1 PMAT A 2 PMAT amp 11 Group Left wall 4p 12 Group Right wall 4 Bell Crank 3 5 Bucket Link The element groups are also used to assign properties needed in Fatigue analyses during Strain Coat Recovery simulations see Section 4 2 1 Element group properties below and Section 6 9 Strain coat analysis Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 2 Element groups n Some Nastran bulk data files may also contain a user defined name of an element set or physica
319. isualizing the model To open the Modeler window click the Show Modeler button on the Windows menu or toolbar The Modeler window is shown below with an example mechanism assembly IT aeix 3 2 2 Modeling toolbars In Fedem there are three major tasks performed by the user 1 creating the mechanism and control system 2 setting up and starting the analysis and 3 setting up and viewing the results Each task has a different set of associated commands The mechanism modeling tools used to create and edit models are covered by the Mechanism Creation toolbar and the Mechanism Tools toolbar Fedem Release 5 0 User s Guide 3 3 3 Mechanism Modeling 3 3 Mechanism modeling tools Loo Mechanism Creation toolbar The Mechanism Creation toolbar shown below contains the mechanical elements used to build Fedem mechanisms see Section 3 4 Creating mechanism elements for instructions on using these commands and Chapter 4 Mechanism Elements for a detailed description of each element 49 VN a BS F AT O 7 V X NOTE An arrow W beside a button indicates that more options can be accessed by clicking and holding down the button Mechanism Tools toolbar The Mechanism Tools toolbar shown below consists of modeling tools Each of these commands is described in the following sections gt D m at wy KK 3 3 Mechanism modeling tools To help you position items with greater accuracy and to simplify the mo
320. it you are using That is a good tolerance when using meters as model database length unit but is probably too strict when using millimeters You will have to adjust this tolerance to some sensible value according to the size of your FE models and the units you work in WARNING When decreasing the tolerance in a model that is built using a large modeling tolerance some of the triads joints might become invalidly attached when reopening the model Buoyancy Buoyancy forces and associated load correction stiffness may be included for Generic Part links if the link is assigned a geometry description file in the Visualization field in the Link property see Part tab in Section 4 1 4 This geometry file has to define a closed volume that represents the total displaced fluid volume when submerged and can be either on the VRML format or Fedem s internal Cad format ftc Fedem Release 5 0 User s Guide 3 25 3 Mechanism Modeling 3 9 Model preferences ss The buoyancy force is computed from that part of the volume that is below the specified sea water level surface and is applied in the opposite direction of the gravitation vector The water surface is a plane with surface normal vector equal the opposite of the gravitation vector and that passes through the point S0 gt 3 lal where s denotes the specified Sea water level and is the gravitation vector The sea water level may either be a constant or a Function of time
321. ize numerical performance of the time integration by adjusting the following parameters You can select Newmark aeS rSn ek in tegration wit h 9 r wit h ou t Tolerances Eigenmode Initial Equilibrium Output n umerical damp ing Integration algorithm numerical damping Q 0 1 within i s recommen d e d Newmark integration with numerical damping HHT alpha factor range D 173 01 You can enable disable the use of Integration tolerances and specify the Maximum and Integration convergence control 2 Use integration tolerances Ignore integration tolerances Number of iteration Minimum number of iterations eorr tenn for each time increment Minimum number of iterations When Ignore in tegration System matrix updates tolerances is set the fixed Fixed number of matrix updates Variable number of matrix updates Number of iterations is specified instead Number of initial iterations with matrix updates Maximum sequential iterations with no matrix update Convergence tolerance factor for matrix updates Q The nonlinear equations are SO l ve d usin g Mo d ifi e d 4 v Geometric stiffness contribution V Centripetal force correction Newton Raphson iterations x Default positioning algorithm for the co rotated link coordinate systems meanin g t h at t h e syste m 5 Max triangle with link scaled offset when necessary xi matrices are not necessarily recalculated in each iteration
322. l 7 35 animation frames 7 25 7 29 load fringes and deformations 7 25 stress recovery options 7 25 animation speed 7 34 animations 7 3 averaging options 7 27 close 7 34 cycling 7 34 deformation results 7 24 eigenmode 7 28 Fedem Release 5 0 User s Guide eigenmodes tab 7 24 fringes tab 7 24 loading 7 24 Modeler window 7 21 Play Panel 7 21 playing repeatedly 7 34 showing continuous motion 7 25 specifying averaging behavior 7 27 speed 7 33 time tab 7 24 anti aliasing 2 26 ASCII format 2 35 D 2 attached elements color 3 21 See also general appearance autoscale 7 7 averaging options 7 27 axial dampers 4 42 axis rotation 2 21 Back view 2 22 Backward Euler 6 2 ball joint 4 28 ball movement 3 10 batch execution of solvers E 1 bdf 2 4 bdf format 1 4 C 1 binary format D 2 binary input blocks adder 5 4 comparator 5 4 multiplier 5 4 binary input control elements 5 4 bmp format 2 35 Bottom view 2 22 Bulk Data File format 1 4 exporting to 1 4 Index l 1 l 2 Index See also bd f C CAE systems C 1 cam joint 4 33 creating 4 33 follower 4 33 cam surface 4 33 Cam thickness 4 36 cam triads 4 33 Centre of Gravity 4 3 centripetal moment correction 6 21 co located items 2 18 Color mapping 7 35 colors for attached unattached elements 3 21 command sensitivity 2 7 commands accessing 2 8 delete all stickers 3 7 detach 3 21 general appearance 2 24
323. l Fast T Showallframes T Continous T Cycle Close You can create several Animation objects and define different options for each animation The created animations can then be loaded into the Modeler window one at a time Animation objects can be set up before or after performing the dynamics simulation and other analyses If you create a certain type of animation and load it into the modeler before performing the simulation you can observe the mechanism motion during the simulation as it is constantly Fedem Release 5 0 User s Guide 7 21 7 Postprocessing Results 7 3 Animations updated see Section 6 11 Interaction during processing Otherwise you can view the entire animation after the simulation is complete When an animation is loaded it can be controlled using the Play Panel see Section 7 4 1 Play panel and the Animation control window see Section 7 4 2 Animation controls The Play panel is displayed in the lower right corner of the Modeler window as shown above when loaded the Animation control window can be activated when needed Graphs plotting values vs time will also be animated in the sense that a time bar showing the time of the current animation frame is shown This time bar is only present as long as the animation is actually showing a time step NOTE You can set up animations at any time and load them however nothing will appear unless the appropriate results are p
324. l Aspects A 7 1 Rolling Resistance Torque For a free rolling wheel at a constant forward velocity without camber and slip angle a drag force rolling resistance is generated Passenger car tires usually have a rolling resistance coefficient between 0 7 1 2 for truck tires the rolling resistance force is usually around 0 5 to 0 7 of the vertical load Note that the parameter q in equation A 80 determines the rolling resistance factor According to the ISO sign convention this drag force as well as the rolling resistance torque M have negative signs dsyi gt 0 In order to reach equilibrium between the force and the torque on the wheel in general a small negative value for the longitudinal slip is obtained A 7 2 Typical Tire Characteristics For pure slip conditions either longitudinal or lateral three typical A graphs can be made F asa function of the longitudinal slip x Fy as a function of the slip angle o M asa function of the slip angle a In Figures A 14 and A 15 examples of these characteristics valid for the W axis system are shown Fedem Release 5 0 User s Guide A 33 A Using the MF Tyre Model A 7 Some Practical Aspects Figure A 14 Longitudinal Force as a Function of Longitudinal Slip 8000 6000 4000 2000 0 a 2000 4000 6000 8000 Figure A 15 The Lateral Force and Self Aligning Torque as a Function of the Slip Angle 8000 1 6000 4000 2000 200 D
325. l Fedem modules 1 Dynamics Solver Mode Shape Recovery Strain Rosette Recovery You can set the maximum number of concurrent processes that will be run during a simulation task This 9 Coat Recovery Summary Qe concurrent processes 1 m Link Reducer Out of core Options e IV Equation solver out of core is useful if you have a Cache size Automatic C Manual J IMB multi processor machine R Recovery matrix out of core and want to run several link Cache size Automatic C Manul 5 Me reductions or recovery a processes in parallel p Remote solve options Perform remote solve e You can fine tune the Remote shell command prefix memory usage of the Link Reducer through these options See Optimizing the Link Reducer memory usage meses mm for further details Model path on remote system vou can specify a command prefix to be applied on all solve tasks except for FE Fatigue and Duty cycle analysis This can be used to launch the simulation tasks on another computer in your local network than the Fedem UI is executed on See Running solver processes on a remote computer below for further details 6 6 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 2 Solver tools CAUTION Many of the solver options listed in Appendix E Command line options may already have been provided to the corresponding solver through their respective Solver Setup dialo
326. l property as a comment line before the set property definition itself When found such comments are parsed and used in the default description of the created element group when the bulk data file is imported into Fedem NOTE The syntax of the comment lines containing names on element sets and properties depends on the software package that produced the actual Nastran bulk data file Currently the syntax of the following packages are supported I DEAS Hypermesh and NX TIP The description field can be edited both for explicit and implicit element groups The modified description is then stored in the link file ftl file To revert to the original description e g PTHICK for implicit groups based on the thickness element property delete the description text completely Any user defined name parsed from a Nastran bulk data comment line is not restored however 4 2 1 Element group properties When an element group is selected in the Model Manager panel its 4 properties are displayed in the Property Editor panel shown below It contains parameters and settings that are used in Fatigue calculations during a Strain Coat analysis on this element group See Section 6 9 Strain coat analysis to learn more about such fatigue analyses Description PTHICK Fatigue parameters Stress concentration factor 1 2 O v Enable fatigue calculation Standard British 7608 1993 x S Neurve F2 l4 This toggle enables
327. l then be computed from the governing constraint equations of the joint However it is also possible to instead specify the initial conditions in the slave triad and let Fedem derive the corresponding joint velocities by inverting the constraints Fedem Release 5 0 User s Guide F Beta feature documentation F 11 Initial conditions for dynamics analysis i F 11 1 Initial velocities in the model file The initial velocity in a triad is specified by entering the following line within the appropriate TRIAD record GL VEL uy uy Uz 6 Wy Oz where u Uy Uz Ox Oy and are the initial velocity components in the global DOF directions of the triad For a joint initial velocities in the joint degrees of freedom may be specified through X TRANS JVAR INIT VEL uy Y TRANS JVAR INIT VEL uy Z TRANS JVAR INIT VEL uz X ROT JVAR INIT VEL oy Y ROT JVAR INIT VEL oy Z ROT JVAR INIT VEL oz where u Uy Uz Ox Oy and o apply in the joint DOF directions Of course you should only enter initial conditions for existing DOFs in the joint e g for a Revolute joint you can only specify Z ROT JVAR INIT VEL F11 2 Initial velocities using description field commands As an alternative to editing the model file the following set of description field commands are available for detailed specification of initial conditions On Link objects InitTransVel ux uy uz On Triad objects
328. l variables When you plot internal control variables you will probably discover that some of the control lines don t have any results The reason for this is that more than one control line share the same control variable and the results appear on only one of these usually the one with the lowest ID This situation will occur when one element s output is used as input to more than one other element Fedem Release 5 0 User s Guide 7 11 7 Postprocessing Results 7 2 Graphs TIP Have the control system editor open during curve result selection If you select a control line in the RDB Selector that line will also be highlighted in the control system editor Vice versa if you select a control line in the control system editor that control line will be selected in the RDB Selector That way you can easily see which control line you will have to plot to get the variable you want Creating curves from file A curve can be created from an external file DAC ASCII or RPC by selecting the From file option on the Property Editor panel s Data tab The panel used to define such a curve is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics r Source E C From RDB Oo o e G From file File Browse Reload C Intemalfunction Channel Nat set 4 or Enable Fatigue bi EN Incomplete Export curve automatically File field The selected file will be listed here Browse b
329. le ments mid Reference to a mass property field for concentrated mass elements nid Reference to a non structural mass field for beam and shell elements oid Reference to an orientation field for this element pid Reference to a material field for this element rid Reference to a component numbers field for rigid elements sid Reference to a stiffness matrix field for spring ele ments For SPRING elements it refers to a PSPRING entry with type 1 whereas for RSPRING elements it refers to a PSPRING entry with type 2 vid Reference to a visibility status field for this element wid Reference to a weight and component numbers field for weighted averaged motion elements C 1 4 Properties The various properties that are used in the structural element expressions have the following syntax PMAT pid e g v p Parameter Value Type Description pid Integer Material property identifier e Real Young s modulus g Real Shear modulus used by beam elements only v Real Poisson s ratio Real Material density Fedem Release 5 0 User s Guide C 5 C FE Link Interface C 1 Fedem Technology Link format PBEAMSECTION gid a iyy izz ixx ky kz cy cz Parameter Value Type Description gid Integer Geometric property identifier a Real Cross sectional area iyy izz Real Moments of inertia about the local y and z axes of the beam ixx Real Torsional stiffness parameter ky k
330. le FE node you must align the master triads of the joints You can then attach the master triads of each joint to the FE node The two master triads will then be merged into one triad shared by the two joints 3 6 2 Surface Connectors The Surface connector commands are used to attach mechanism AE elements to FE parts at positions without existing FE nodes E g center of holes etc or in such a way that the Surface connector distributes the forces from the joint load etc onto some area on the FE model Surface connectors connects a triad to an FE model using two different connection types Rigid Surface or Flexible Surface Flexible surface The flexible surface connector acts as a force distributor It does not introduce stiffness or constraints between the FE nodes it connects to but distributes the forces from the triad onto the FE model Each nodal DOF gets an equal share of the translational forces it the triad The moments acting on the Triad and the moment created by the translational forces about the geometrical center of the nodes is balanced by an additional force in each node weighted by the nodes distance from the geometrical center of the nodes in the Surface connector In the case where the nodes also have rotational degrees of freedom shell nodes those rotational degrees of freedom also gets an equal share of the moment The Flexible surface connector is visualized with dotted lines Rigid surface vo
331. le of for SWIFT Tyre B 34 Rolling resistance torque formula for MF Tyre A 33 rotate F3 2 21 rotating about a point 2 21 about an axis 2 21 selecting new point 2 21 rubber bushings 4 26 Run option E 1 Runge Kutta method Lobatto IIIC 6 2 S sample and hold block 5 5 Save As command 6 48 screw ratio 4 32 second order accuracy achieving 6 2 second order transfer function block 5 7 Select 2 21 select 2 13 select dynamic center F4 2 21 selecting items in the Model Manager 2 9 selection 2 18 selection filter 2 18 selection history 2 18 sensors 4 64 managing 4 65 processing data 4 64 simple 4 65 Show All Frames forcing option 7 34 Simplified visualization 4 3 simulating nonlinear behavior 5 5 simulation graphed results 7 3 managing results 7 2 progress indication 6 47 Fedem Release 5 0 User s Guide simulation results dependent on 1 5 Simulink 5 11 singularities 6 12 Singularity criterion 6 14 slave triad follower 4 33 Slip formulas for MF Tyre A 18 Smart Move 3 5 3 8 3 10 from point and to point 3 11 motion constraints 3 6 performing 3 11 3 13 selecting multiple items 2 18 stickers 3 6 types of motion allowed 3 10 using 3 6 S N curve 4 17 snap 2 17 stickers 3 6 3 8 applying manually 3 6 creating manually 3 7 deleting 3 7 storage 2 3 eigenvalues from dynamics simulation 8 10 Fedem Link Model 1m format 2 3 Fedem M
332. le to complex models B 21 tire rolling radius B 14 symbols line smoothing 2 26 system requirements 2 1 2 2 See also hardware requirements system resources 6 47 T target point 4 47 3D animation 6 47 modeling stickers 3 10 point marker 3 5 viewing 2 14 dynamic updating 6 47 3D View Control toolbar View menu 2 22 3D viewing 2 25 commands 2 22 time history changing interval 7 25 Time History Animations 7 24 time integration optimizing numerical performance 6 20 time step iterations 6 47 Time summary animations 7 24 time window 7 25 time dependent control blocks delay 5 5 sample and hold 5 5 tire data file 4 49 Tire model 4 49 4 53 Tire property files example for SWIFT Tyre B 28 Tire relaxation length described for MF Tyre A 30 Tire rolling radius in MF Tyre A 8 in SWIFT Tyre B 14 Tire slip quantities in MF Tyre A 11 Tire road interaction in MF Tyre A 3 toolbars 2 8 3D View Control 2 7 Control Creation 2 8 5 2 Control Tools 2 8 5 3 managing 2 8 mechanism tools 2 7 Solvers 2 7 standard 2 7 Windows 2 7 Zoom and Pan 2 7 top view 2 22 Topology List 2 11 torques 4 46 tpf file 4 49 translational motion restraining 3 6 triads 3 2 4 2 4 18 about 4 18 adding mass and mass inertias 4 19 additional boundary conditions 4 19 attachment restrictions 3 16 color representations 4 18 connections 3 2 4 18 constrained DOFs 4 20 coordinate system 4 19 editing
333. les A special type of function definitions are the Time history input file object This object behaves essentially as a function of time but is optimized to be used for input of time history data from an external files Fedem Release 5 0 User s Guide 4 63 4 Mechanism Elements 4 11 Sensors 4 11 4 64 Creating a Zoom To To create a Time history input file object E eom right click in the Model Manager Objects rm fi Damper characteristics Sort by Name R Friction 5 list select Create and Time history input file Anew object will then be created Delete Del F Function and its properties are displayed in the Es Time history input fle Property panel Road elevation C External Control System Properties amp File Reference The behavior and options for this object is the same as for the Polyline from file function type except that it is always a function of time See Section 4 10 5 Function Types Sensors Sensors are used to measure movement and other variables associated with mechanism elements during the dynamics simulation They work mostly as Tags to show what objects are being measured Objects that have a sensor attached will appear in the Argument drop down list in Functions and Control Inputs They are created automatically when selecting an Argument by using the Select Argument button in the Function and Control Input property panel See Section 4 10 2 Function properties and Sec
334. line segments It is not possible to remove line points segments if doing so reduces the line to less than three segments NOTE Changing the path or breakpoints of a line is for display purposes only and has no influence on control system performance Rotating blocks You can rotate control blocks 180 so that the input connections are on the right side of the block and the output connections are on the left side of the block To rotate a block click the Flip Element Direction button on the Control Tools toolbar and select a block Press Done to confirm the selection NOTE This command is for display purposes only and has no influence on control system performance Deleting blocks or connections To delete a block or connection line in the Control Editor complete the following steps 1 Select the line or block in the Control Editor window NOTE You can select multiple blocks at the same time by selecting them in the Model Manager Objects list 2 Click the Delete button on the Standard toolbar or the delete key on the keyboard The selected objects are removed from the control system NOTE When you delete a block all connection lines to and from the block are also removed Fedem Release 5 0 User s Guide 5 Control System Modeling 5 5 External control systems 5 5 External control systems 5 5 1 Requirements The use of external control systems modeled in Simulink requires MATLAB to be installed on your compu
335. lists of all the objects and result views that make up your model This includes mechanism modeling and control system objects along with animations and graphs In each list objects are grouped by type and sorted by Objects Results Axial springs eo E t amp R Frictions om F Functions PORE F Functions e t Spring characteristics E f x Unconverted functions Not used identification numbers or names In the 3 8 Gears Model Manager right click menus can E Joints access several commands that can be Mosen 1 PowerUnit to Nozzle 2 PowerUnit to Nozzle 3 Transmission shaft 4 Gearbox 1 to ball screw connection 5 Gearbox 3 to ball screw connection B Transmission shaft 2 Z Transmission shaft 3 8 Gearbox 2 to ball screw connection El E Prismatic joints amp y Revolute joints applied to the selected objects NOTE The Objects and Results lists are empty or nearly empty until you create items Selecting items In the Model Manager you can select items in several ways m FE Rigid joints H 4f Links Highlight a single item EtLoads M Ref l gt Hold down the Shift key and click i multiple items Triads gt Hold down the Ctrl key and click 4 gt multiple items or a single item to select deselect Click and drag the mouse over multiple items Deselecting items To deselect all items right click an empty space in
336. ll be left untouched unless it is an internal repository Internal repositories will be deleted when switching to an external repository If there exists files with the same names at the new destination fedem will try to find out wether the reduced data match the existing FE model If it does the reduced data will not be copied as identical data is assumed to exist at the new destination Fedem Release 5 0 User s Guide 4 15 4 Mechanism Elements 4 2 Element groups 4 2 Reusing a link from an existing link repository To import and reuse the reduced data for a link the link can be imported from the existing link repository using the Load Link command See Section 4 1 1 Creating links by file import Select the ft file you want and toggle on the Use link specific repository toggle in the Import Link dialog You will then need to add triads and reducer options for that particular link that match the options and triad positions used by the previously reduced link When done Fedem will detect the reduced files and flag the link as Reduced Element groups When a link is created by importing a FE model into Fedem several element groups might be created as well see Section 4 1 1 Creating links by file import The element groups can be of the following two types Explicit groups User defined group through Nastran SETs on bulk data files or Fedem GROUPs on t 1 files Implicit groups An implicit element group cons
337. ls a and b may both be numbers functions or the independent variable x Function Description abs a absolute value atb addition a b subtraction a b multiplication a b division a b power sqrt a square root n a nth root sin a sine cos a cosine tan a tangent asin a arcsin acos a arccos atan a arctan in a logarithm base e log a logarithm base 10 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 10 Functions Function Description exp a exponential e aEb a 10P pi constant value of x Available logical operators Function Description a not a b less than a gt b greater than a lt b less than or equal to a gt b greater than or equal to a b equal to al b not equal to a b or a amp amp b and Constant fv Fedem Release 5 0 User s Guide fog e C constant amplitude 4 57 4 Mechanism Elements 4 10 Functions Linear function Jv Step ftv Ampl Start Ampl L L L L Delay Ramp SQ Start Ampl f L L L Delay 4 58 f v kv k slope fe 5 CHA v vg C offset start amplitude A amplitude Vo Step abcissa value delay fo C VSV Ct k v vo v vg C offset start amplitude k slope vo ramp start abcissa value delay
338. lue analy 0 sis negative value captures zero fre quency modes s Guide E 7 E Command line options E 3 Dynamics solver options fedem_solver E 8 Command line option Description Default value eiginc Time between each eigenvalue analysis 0 factorMass_eigen Factor mass matrix in eigensolver false solver fao Read additional options from this file fco Read calculation options from this file flushinc Time between each database file flush 0 0 0 Do not flush results database let the OS decide 0 0 Flush at each time step no external buffers 0 0 Flush at specified time interval use external buffers fop Read output options from this file frsifile Name of primary response database file th p frs frs2file Name of secondary response database file th s frs fsi2file Name of additional solver input file fsifile Name of solver input file fedem solver fsi GSFsolver Use the GSF sparse equation solver false help Print out this help text false ignoreIC Ignore initial conditions from the fsi file false initEquilibrium Initial static equilibrium iterations false JacobiPerturb Relative perturbation for computation of 1e 005 numerical Jacobian in control iterations lanczi Use the LANCZ1 eigensolver false licenseinfo Print out license information at startup false licensepath License file
339. lyline and Polyline from file gt Constant Linear Ramp Limited Ramp A more detailed description of the spring characteristics can be found in the Fedem R5 0 Theory Guide Section 5 1 Spring Elements Damper characteristics The four types of damper characteristics are Force Velocity Torque Angular velocity gt Coefficient Velocity gt Coefficient Angular velocity Fedem Release 5 0 User s Guide 4 43 4 Mechanism Elements 4 7 Springs and Dampers Force Velocity Torque Angular velocity These characteristics describe the relationship between the damper velocity and damper force torque directly If a function g v is used the damper force is F v g v forall v The damping coefficient is computed as the derivative g v A regular damper will have a g v that is positive for positive v and vice versa Coefficient velocity Coefficient Angular velocity These characteristics are interpreted as the derivative of the force torque velocity function with respect to v The damper force at a specific v is thus F v ig ondw fora given function g v and the damping coefficient is the function value directly A regular damper will have a coefficient velocity function with positive values only The damper characteristics can be defined using the same function types as for the spring characteristics see Spring characteristics above A more detailed description of the damper characteristics ca
340. may severely hamper the performance as it is forced to write small data amounts to disk at a very high frequency In such cases using a value less than zero or much greater than the time step size is recommended Monitoring the most problematic DOFs during time integration For complex models it is not likely that the dynamics simulation will run smoothly in the first attempt Usually some fine tuning and or model correction will be required before a converged solution can be obtained To aid the debugging of problematic models the degrees of freedom that get the largest solution increments during the non linear iterations will be listed in the res file when the simulation experiences convergence problems Often the problem can then be identified by studying the elements related to these DOFs and verifying that their geometry and or properties are sane 1 The size of the internal file buffer is platform dependent Consult the technical documentation on your computer operating system to find out how big it is Fedem Release 5 0 User s Guide 6 29 6 Mechanism Analysis 6 5 Dynamics analysis a Fedem will produce those messages when the convergence criteria employed see Tolerances tab in Section 6 5 1 increases in two or more consecutive iterations or the number of iterations is getting close to the maximum number of iterations specified It is then assumed that a convergence problem is encountered and the specified number
341. ments 4 4 Joints case Refer to Section 4 4 4 Prismatic joint and Section 4 4 4 Cylindric joint for further details The behavior of the joint variable can be controlled or customized in several ways There are four main options Fixed This DOF is fixed and can not be moved It is removed from the system of equations condensed out Free This DOF is free to move No constraints are applied This is the default setting Prescribed This DOF can be assigned a prescribed motion and is thus condensed out from the system of equations Spring Damper This DOF is free to move but a spring and a damper may be applied to assign stiffness and or damping properties to it Integrated springs and dampers When setting a joint variable to be spring and damper controlled the joint springs and joint dampers are initially inactive their properties including spring stiffness and damper coefficient are initially set to zero You can then assigning values to the joint s spring and damper properties in the Property Editor panel see Section 4 4 2 Joint properties and Section 4 7 Springs and Dampers for more information about the behavior of springs and dampers The integrated springs and dampers are listed in the Topology List of the joint as separate items they are however not listed in the Objects list in the Model Manger You can access the full property panel for the joint springs and dampers by dou
342. mn a MV Use path relative to model file location Use link specific repository for this link 2 Select the file type you are looking for from the File type pull down menu 3 Browse for or enter the path and filename of the link file in the File Name box TIP You can import more than one link at the same time by holding down the Ctrl or Shift key and selecting multiple files in the Open dialog 4 Select the units conversion you need from the Unit Conversion pull down list All units used in the file for dimensions and properties are converted according to your selection WARNING There is no connection between this unit conversion and the model database units You must be careful to choose the conversion that fits your needs A TIP You can add your own unit conversions by editing the file units fcdinany ASCII text editor This file is located in the Fedem installation directory 5 Make sure that you want to store the relative path to the original FE model or the VRML model This setting is relevant when copying and moving the model across file systems and has most impact on VRML files The path to the original FE model file is only used if the internal FE model copies are lost 4 4 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links 6 Indicate if you want this link to be a part of the model link repository or if it should be stored with a link specific repository See Section 4 1 5 Using link reposi
343. modeling tools 1 Select a point in the Modeler window The coordinates of the point given in the local coordinate system for the selected element are displayed in the Interactive Odometer and the 3D Point Marker shows the location of the point selected 2 Select Local or Global coordinates from the Reference pull down menu 3 Type new values for the X Y and Z coordinates in the Interactive Odometer and press the Enter key after editing the values The 3D Point Marker is updated to show the new position 4 When you are satisfied with the new location press Done to confirm the selected point 3 3 3 Stickers Stickers are movability constraints that are applied automatically when moving mechanism objects with the Smart Move command see Section 3 5 Moving mechanism elements Stickers can also be applied manually see Manually applying stickers below Each sticker applies the same constraint as a ball joint in other words it constrains all translational motion Stickers are displayed in the Modeler as small pyramids A shown at right The tip of the pyramid is located at the constrained point When using Smart Move the motion allowed or A movability for a selected object or group depends on the number and location of applied stickers Each move using Smart Move automatically applies an additional sticker Therefore three successive moves of an initially free object without stickers first results in a tr
344. mple interval should be in the range of 0 1 0 2 meters or larger For the road data given below the value of ROAD INCREMENT should be set to 0 1 meter FILE TYPE rdf FILE VERSION 5 00 FILE FORMAT ASCII COMMENTS comment string polyline style road description UNITS UNITS MASS Ug LENGTH meter TIME sec ANGLE degree FORCE newton B Using the SWIFT Tyre Model B 6 Road Property File Example N Gates kiena Sees eee pe eee eee ees MODEL MODEL METHOD 2 ROAD_TYPE poly_line Se ee a ee eee PARAMETERS PARAMETERS OFFSET 0 ROTATION ANGLE XY PLANE 0 MU 1 XZ DATA 10000 0 0 0 0 0 9 1 0 0 0 2 0 0 0 3 0 0 0 4 0 0 9 5 0 01 0 01 0 6 0 0 0 7 0 0 0 8 0 0 9 9 0 0 1 0 01 0 01 1 1 0 02 0 02 1 22 0 02 0 02 1 3 0 02 0 02 1 4 0 0 1 5 0 0 1 6 0 0 1 7 0 0 1 8 0 0 1 9 0 02 20 202 2 s 02 0 02 2 1 0 02 0 02 2 2 50 01 0 01 23 10 93 0 01 2 4 0 0 225 0 0 2 6 0 0 2 7 0 02 0 02 2 8 0 02 0 02 259 0 02 0 02 3 0 015 0 015 3 1 0 01 0 01 3 2 0 005 0 005 343 0 004 0 004 Fedem Release 5 0 User s Guide B 35 B Using the SWIFT Tyre Model B 6 Road Property File Example i 344 0 003 0 003 3 5 0 002 0 002 3 6 0 001 0 001 Sd 0 0 3 8 0 0 359 0 0 4 0 0 0 10000 0 0 B 36 C FE Link Interface es Appendixc FE Link Interface Finite Element
345. n be flexible and can experience large elastic deflections and coupling effects To ensure sufficient accuracy the simulation solver must account for the mutual dependencies between dynamic properties at the system level and structural flexibility at the component level These requirements can be efficiently satisfied through a non linear structural dynamics approach In Fedem a non linear structural dynamics approach is utilized in order to simultaneously solve structural deformations and 3D motion dynamics in the time domain The mechanical assembly to be simulated is comprised of parts each represented by a linear elastic finite element model or a simplified stiffness description and coupled together with linear or non linear joints After a DOF reduction of each finite element part based on a dynamic super element formulation the system equations are assembled and solved with respect to finite element degrees of freedom allowing large translations and rotation due toa co rotated theory 1 3 Control systems in mechanical analysis A mechanical system is often in a control loop including sensors measuring states in the mechanism compensators representing control algorithms and servo hydraulic or electrical actuators that generate the energy to drive the mechanism These control modules and the mechanism must be integrated simultaneously in order to ensure sufficient accuracy of the simulation results To model your control systems
346. n be found in the Fedem R5 0 Theory Guide Section 5 2 Damping Elements Creating spring and damper characteristics To create a spring or damper characteristic right click in the Model Manager Objects browser and select Create gt Spring Damper Characteristic and then the type you want from the menus shown below t Spring characteristics t Adv Spring Characteristics Translation t Spring characteristics P Hj Damper characteristics Adv Spring Characteristics Rotation H Damper characteristics gt ch Coefficient Velocity F Function Ke Stiffness Translation F Function ty E Time history input file F Force Translation E Time history input file DG Coefficient Rotational vel Road elevation KG Stiffness Rotation Road elevation TG Torque Rotational Velocity C External Control System Tg Torque Rotation C External Control System ERTS Pre e Ere The characteristics you have created will be displayed in the proper pull down menus in the spring and damper property panels Only the ones of correct type will be listed to avoid using characteristics defined for rotation in translational DOFs and vice versa 4 7 6 Advanced spring characteristics In addition to the basic spring characteristics types described above there are also some more advanced characteristics available with further 4 44 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 7 Springs
347. n the FE models used To create a satisfactory model of a real structure the analyst must combine insight into the nature of the problem experience with the Finite Element Method and knowledge of the general rules of FE modeling B 1 6 CAD integration Fedem has an integration with several SolidWorks based cad systems This includes native SolidWorks NEiFusion and our own CAD editor add on FedemSolid This integration makes it possible to transfer a complete CAD assembly to Fedem and use it as a starting point for the Fedem model The Fedem model can then be updated when the CAD assembly changes See Section 2 12 Using the CAD integration for more details In addition see Section 4 1 Links CAD geometry from VRML files wrl vrml vrl wrz can be imported directly 17 Fedem solver modules Fedem uses separate program modules to perform the different type of calculations on the model Thus there are modules for model reduction dynamic mechanism simulation stress and mode shape recovery strain rosette analysis strain coat analysis and automated curve export The main Fedem application manages the execution of each module However they may also be run separately as batch processes The Fedem solver modules are described briefly below TIP To display a list of all the modules and their version and build date press the About Fedem entry in the Help menu Fedem Release 5 0 User s Guide 1 5 1 Introduction to Fed
348. n the component of rotation vector as defined in the Fedem R5 0 Theory Guide Section 2 3 3 Rodriguez parameterization The default is to measure Euler Z Y X angles F9 Generic database objects A generic database object not to be confused with Generic Part links can be used to access new and undocumented features in the dynamics solver A generic database object is created by selecting Generic DB Object from the Mechanism menu The object is manipulated edited and deleted in the same way as for the other Fedem objects CAUTION The contents of the Type and Definition fields of the Generic object property panel is used as direct input to the dynamics solver and may thereby change the computed response This feature should only be used with guidance from Fedem support personnel F Fedem Release 5 0 User s Guide F 9 F Beta feature documentation F 10 Prescribed Triad motion F 10 F 11 Prescribed Triad motion A predefined prescribed motion may be imposed directly on Triad degrees of freedom A generic database object see Appendix F 9 Generic database objects may be used to define such motions in terms of a Function and or a constant value The Type and Definition fields of the Generic object property panel then need to contain the following Type MOTION Definition triadld triadld IDof lt Idof gt type deflection d0 d0 d1 1 0 motionEngineld lt functionld gt where lt triadid gt a
349. n then be used to control the magnitude of loads changes in spring length and so on E The output block is used to make a response variable from the control Y The Control output has the option to use an embedded function to alter the output from the control system before it is applied to the mechanism This function is edited in the same way as Functions See Section 4 10 2 Function properties Fedem Release 5 0 User s Guide 5 3 5 Control System Modeling 5 3 Control blocks 5 4 5 3 Control blocks Control blocks also called control elements calculate the output as a function of one or more inputs and the block s internal state When a control element is selected in the Control Editor its mathematical equation and properties are shown in the Property Editor panel see Section 5 4 4 Editing block properties For more information about individual control elements see the Fedem R5 0 Theory Guide Chapter 8 Control System The following sections describe the control elements available for use in Fedem control systems Amplifiers The control system supports the two types of amplifiers described below Amplifier block The Amplifier block amplifies the input signal with a user defined value Power block The power block calculates and outputs the power n of the input signal x where nis specified by the user Binary input blocks Binary input control elements have two input signals The binary input
350. n to the right gt Ball when one sticker or one ball joint has been applied to a mechanism entity it can rotate about the point at which the sticker joint is applied The symbol for ball movement is depicted in the Modeler as shown to the right Revolving when two stickers or one ball joint and one sticker or two ball joints have been applied to a selection of mechanism elements the stickers joints act together as a revolute joint with the axis defined by the line between the two stickers joints The symbol for revolving motion is depicted in the Modeler as shown to the right 3 10 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 5 Moving mechanism elements cylindric when a selection of mechanism elements is constrained by one cylindrical joint the selection can be translated along and rotated about the joint axis The symbol for cylindrical motion is depicted in the Modeler as shown to the right Prismatic when a selection of mechanism elements are constrained by one prismatic joint the selection can be translated along the joint axis The symbol for prismatic motion is depicted in the Modeler as shown to the right Rigid when three stickers or ball joints not located on a straight line are applied to a selection of mechanism elements the selection is fully constrained and cannot be moved with the Smart Move command The symbol for rigidity no movement allowed
351. naged in the Model Manager Objects list If you have created frictions you can expand the Friction group to see a list of the frictions in your model Selecting a friction from the Objects list displays the friction properties in the Property Editor panel Each type of friction has a different image and parameters associated with it The figure below shows the Property Editor panel with prismatic joint friction selected Description f Type Parameters Distance to locking device A 1 000000 Bearing constant Y 00 Force caused by prestress Boo Coulomb coeff Jao Magnitude of Stribeck effect S ja 0 Critical Stribeck speed Vslip 0 0 To edit the friction enter new values for each of the friction parameters listed in the Property Editor panel See the Fedem R5 0 Theory Guide Section 6 6 Joint friction for a description of friction parameters ur TIP To associate the friction with the appropriate joint select the joint and edit its friction properties in the Property Editor 47 Springs and Dampers There are two types of springs and dampers in Fedem Axial and joint springs and dampers An axial spring or damper applies relative forces between two triads along the direction between the triads Joint springs and dampers are integrated in the joint and act on the joint triads along one of the joints unconstrained DOFs see Section 4 4 1 Joint variables
352. nal data or other fields can be referred to using this field reference and id Field reference reference specified in combination with a valid ID text Can be used as additional informa tion for a field reference or as an optional tag e g a group name Denotes required text The following are examples TET4 4 22 34 12 32 PMAT 1 A constant strain tetrahedron element with ID 4 referring to nodes 22 34 12 and 32 The element uses an attribute of type PMAT material property with ID 1 PMAT 1 2 10e 11 8 00e 10 2 900e 01 7 82e 03 A material property entry with ID 1 and four decimal numbers describing the different parameters in the material Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format NOTE All text between a comment symbol and the end of the line is ignored C 1 2 Nodes Nodes are expressed by the following syntax NODE id state x y z Parameter Value Type Description id Integer External node identifier state Integer Internal external state flag 0 an internal node condensed out in the reduction 1 an external node retained in the reduction XYZ Real Global nodal coordinates C 1 3 Structural elements Elements are expressed in several ways depending on the element type Each element type is expressed by one of the statements in the table below Element statements BEAM2 id n1 n2 PMAT pid PBEAM
353. nalysis iisi iiien rinii E Ea mme 6 4 Solver tool Suis m E ETE 6 5 6 2 1 Solvers Toolbar aea ee RYE ERU ERR V EATE AR E t 6 5 6 2 2 Controlling placement of temporary files cece eee eee eee ee 6 5 6 2 3 Additional solver options 0 cece cece cece ence ence ee 6 6 Fedem Release 5 0 User s Guide ix 6 3 6 4 6 5 6 6 6 7 6 8 6 9 6 2 4 Link and group wise solving cece cence cence ence eee en enenee 6 8 Model Seduction senii ass aeo unde cada ER aate d eae 6 10 6 3 2 Using component MOdeS 0 cece cece eee mee 6 11 6 3 3 Using lumped mass matrix 0 cece eee eee cence e 6 12 6 3 4 Handling singularities during the model reduction 6 12 6 3 5 Eigenvalue analysis of the reduced links ssesseueeseuues 6 14 6 3 6 Visualization of eigenmode shapes from the model reduction 6 15 6 3 7 Reduction of applied load vectors 0 cece cece ence eee cece eeee 6 15 Model reduction in Nastran cece e eee cece eee eee eee 6 16 D ynamics analvsis s oho se incisa cose e aru 6 18 6 5 1 Dynamics Solver Setup 00 cece eee eee e eee me 6 18 6 5 2 Result output CONTOl 2 cece eee cen ence teen ence ene e ences 6 26 6 5 3 Monitoring the most problematic DOFs during time integration 6 29 6 5 4 Starting the analysis 0 cece cee cece cence ene 6 30 6 5 5 Handling singularities during the dynamics analysis
354. nd functionld are the base IDs of respectively the Triad at which the motions should be applied and the Function defining the time variation of the motion Furthermore lt dof gt is the local DOF number range 1 to 6 of the Triad and dO is a time independent constant motion value If the prescribed motion should not have any time variation at all it is sufficient to specify a non zero d0 and then leave out the d1 1 0 and motionEngineld lt functionld gt fields NOTE The base ID of a mechanism object is normally not visible in the Fedem UI To see the base ID you have to launch Fedem in debug mode using command line option debug Then the base ID appears in curly braces in the Object Browser Initial conditions for dynamics analysis It is possible to specify different initial velocities for all Triad and Joint degrees of freedom either by editing the model file mm or by entering description field commands These settings will override the global initial velocity defined in the Model Preferences dialog for the affected objects Of course this should be used with care such that the velocity state specified this way is consistent throughout the model If that is not the case fictitious transients will occur in the first time steps of the analysis When using initial conditions it is recommended to specify initial velocities for the joint DOFs also The initial velocities at the slave triad of the joint wil
355. near model See also the Fedem R5 0 Theory Guide Section 8 4 3 Piecewise continuous elements Logical Switch block T The Logical Switch block returns one of two predefined constant inputs both of which are dependent upon the value of a third input called the control input If the signal of the control input is greater than or equal to the threshold parameter the block returns the user specified upper limit otherwise it returns the user specified lower limit Fedem Release 5 0 User s Guide 5 5 5 Control System Modeling 5 3 Control blocks 5 6 T i5 3 s E 4 4 4 4 Limiter block The Limiter block imposes upper and lower bounds on a signal When the input signal is within the user specified range of the upper and lower parameters the input signal passes through unchanged When the input signal is outside these limits the signal is limited to the upper or lower limit Dead Zone block The Dead Zone block generates zero output within a specified range called its dead zone The lower and upper limits of the dead zone are specified as the Left and Right parameters in the Property Editor panel The block output depends on the input and the dead zone as follows If the input is within the dead zone greater than the lower limit and less than the upper limit the output is zero If the input is greater than or equal to the upper limit the output is the input minus the upper limit If t
356. need to attach the object to a Link using the Attach command See Section 3 6 Attaching and detaching elements TIP To edit the properties of a new mechanism element select the item in the Modeler or Model Manager Objects list The properties of the item are then displayed in the Property Editor panel 3 4 4 Selecting position and orientation When creating mechanism elements you are asked to select their position Revolute joints Free joints Loads and Cam joint master triads will be created with a default orientation as well As you select a point Fedem will snap to geometric features and also extract a default orientation if necessary by different rules depending on what type of part object you hit 3 8 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 4 Creating mechanism elements Snapping and default orientation on FE Parts When picking an FE Element surface the default orientation is set to be perpendicular to that surface and the position snaps to the closest node If the exact position of the mouse is on an FE mesh line however the default orientation is aligned with the direction of that line It is the exact mouse position that decides whether you hit a line or a surface even when the 3D Point Marker snaps to the same node Snapping and default orientation on CAD Parts Position options If the mouse position is on a CAD part the geometry of the face or edge is lo On Center used to extract a default ori
357. ness proportional damping it is the unscaled mass and stiffness matrix that contributes to the damping matrix and force vector Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links WARNING The mass and stiffness scaling is not accounted for during FE link reduction Therefore the component mode shapes are always computed from the unscaled mass and stiffness matrix Using stiffness and or mass scaling onan FE link having component modes might thus yield inaccurate results unless the two scaling factors are equal because the component modes then are computed from a different set of matrices than the one used in the dynamics simulation Visualization Generic Parts only This frame contains options and information regarding the visualization of the Generic Part The File field can contain a path to a VRML file to use as a visualization for the Generic Part Press the Change button to browse for a file If a valid FE model file is already referenced fedem will use that as a visualization until a VRML model file name is entered Origin tab The Origin tab is used to display and edit the position and orientation of the link See Section 3 5 4 Origin property for a description of the data fields in this tab a Part Origin eduction Options Advanced Position r Orientation Reference CS Coordinate type Reference CS Coordinate type Global 7 J Cartesian XYZ s Global S EuleiZYX asx Y Z x
358. ng by functions is automatically created in the Simple Sensors group To each output there will be a corresponding variable in this sensor Thus in this example a variable ctrlOut will appear as the only variable of the new sensor NOTE The format of the output data from the Simulink model specified on the Workspace I O tab in the Simulation Parameters window under the Simulation menu must be Array 5 12 Fedem Release 5 0 User s Guide 5 Control System Modeling 5 5 External control systems ni NOTE The output options specified on the Solver tab in the Simulation Parameters window under the Simulation menu should be Refine output with the Refine factor set to 1 5 5 4 Performance The co simulation with an External Control System is based on the same principles as with the internal control module Thus the Simulink model is invoked on each iteration and re integrated over the Fedem time step However the Simulink integration may take several steps for each time step in Fedem The number of steps together with several other choices is set in the Simulation parameters window of the Simulink model view A variable step algorithm determines its own step length depending on specified limitations By default the static equilibrium of the Simulink model is found and inserted upon startup The complete integration for each time step in Fedem together with the data exchange via the MATLAB workspace limits the total perf
359. ng function appears to read Gs cos C arctan B Kk E B k arctan B A 75 cos Care tan UB P Hye E p B yks Hye arctan Ge Suy iD Table A 13 Lateral Coefficients Combined Slip Name used in tire rox Name property file Explanation By1 RBY1 Slope factor for combined Fy reduction By2 RBY2 Variation of slope Fy reduction with alpha rBy3 RBY3 Shift term for alpha in slope Fy reduction ICy1 RCY1 Shape factor for combined Fy reduction rey1 REY1 Curvature factor of combined Fy rey2 REY2 Curvature factor of combined Fy with load l Hy1 RHY1 Shift factor for combined Fy reduction l Hy2 RHY2 Shift factor for combined Fy reduction with load ryy1 RVY1 Kappa induced side force Svyk Muy Fz at Fznom rvy2 RVY2 Variation of Svyk Muy Fz with load rvy3 RVY3 Variation of Svyk Muy Fz with camber fyy4 RVY4 Variation of Svyk Muy Fz with alpha rvy5 RVY5 Variation of Svyk Muy Fz with kappa rvy6 RVY6 Variation of Svyk Muy Fz with atan kappa Fedem Release 5 0 User s Guide A 27 A Using the MF Tyre Model A 6 Steady State Magic Formula Formula Aligning Torque Combined Slip M t F M s F A 76 with t 0 eq A 77 D cos Cgarctan Ba eq EB Oy s arctan B o eq eos a Fy y 0 7 Fy7 Syy A 78 M M 0 aj D cos arctan B a cos a A 79 s Ssz1 Ss29 F F 9 5 23 T S 4df Y i Ro g As A 80 with the arguments 2 Ky 2 Q eg 7 a
360. ngle is defined as degrees from the positive x axis select a road definition file by choosing Browse or select a file reference NOTE There is currently no visualization of the road in the modeler Road elevation Road elevations are dedicated functions that are used to describe a road surface To create a Road elevation right click in the Model Manager Objects view and select Create Road elevation You can then edit the road elevation properties in the Property Editor panel in the same manner as for functions see Section 4 10 2 Function properties Functions Functions can be used to control the magnitude of loads length of springs prescribe motion in joints etc The function defines an input variable and a function shape that is used to transform the input value into the output value of the function The output will thus change during the simulation depending on the variations in its input value The input value can be a system variable measured by a sensor the output of a control system the output of a different function or simply the simulation time The function shape can be defined in several different ways and uses a common way of defining function shapes across different objects needing to do so Road elevations Control inputs Control outputs Spring and Damper characteristics are all examples of objects using a similar way of defining function like relationships The description found here is thus valid for
361. nse database file s to restart from restarttime Physical time for restart 1 lt 0 No restart but regular simulation rpcFile Get number of repeats averages and points per frame and group from this RPC file saveinc2 Time between each save of secondary 0 variables saveinc3 Time between each save for external 0 recovery saveinc4 Time between each save of control system 0 data savestart Time for first save to response database 0 scaleToKG Scaling factor to SI mass unit kg 1 scaleToM Scaling factor to SI length unit m 1 scaleToS Scaling factor to SI time unit s 1 skylinesolver Use skyline solver false stopOnDivergence Number of warnings on possible diver 0 gence before the dynamics simulation is aborted 0 no limit Fedem Release 5 0 User s Guide E 9 E Command line options E 3 Dynamics solver options fedem_solver Command line Description Default value option P stressStiffDyn Use geometric stiffness for dynamics false stressStiffEig Use geometric stiffness for eigenvalue false analysis stressStiffEqu Use geometric stiffness for statics false stressStiff Number of iterations without updating 0 UpdateSkip stress stiffening always updated in pre dictor step targetFrequency Target frequency for auto stiffness calcu 10000 Rigid lation terminal File unit number for terminal output 6
362. nt The complete system is considered a five DOF joint that constrains only a rotational input displacement to a translational output displacement The joint also has a transmission ratio similar to that of gears Rack and Pinion symbol The Rack and Pinion symbol p shown at right is displayed in the Modeler as a line between a prismatic and a revolute joint Transmission ratio You can specify the transmission ratio dimensionless rate for a Rack and Pinion constraint in the Property Editor panel see Section 4 5 1 Gears 46 Frictions Joint friction is based on the forces moments and velocity in a joint These forces and moments give an equivalent load which is the basis for computing the friction force For a detailed description of friction behavior see the Fedem R5 0 Theory Guide Section 6 5 Joint friction 4 38 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 7 Springs and Dampers You can create a friction by ono right clicking an empty space in PRS io characteristics the Model Manager Objects list ed pp etd cmd 5 Sort by Name Friction ENTERS selecting Create Friction and then 5 oa tm 4 D Mee the desired friction type You can B Time history input fie Ra Bearing Friction also access this command from Road elevation Ra Prismatic Friction the Mechanism menu in the main window C External Control System la File Reference Re Cam Friction Frictions are ma
363. o create these items either by using the New Graph and New Curve commands or by dragging results from the Result Selector into the Result list of the Model Manager as described below Graph Ex To create a graph select New Graph from the Result menu or right click D in the Model Manager Results list select New Graph An object titled New Graph is listed in the Model Manager Results list Curves To create a curve complete the following steps 1 In the Model Manager Results list select the graph to which you want to add the curve 2 Select New Curve on the Result menu or right click the graph in the Model Manager Results list select New Curve 3 Alternatively If right clicking an empty spot in the Model Manager Result list selecting New Curve a new graph with one curve will be made An object named New Curve is then listed under the current graph in the Model Manager Results list 7 4 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs NENNEN Creating curves and graphs by drag and drop When you need to create several curves and graphs containing results form the results database or want to inspect several result values without the need to create persisting graphs for all of them it is convenient to use the drag and drop method to create and sort curves and graphs To create curves or graphs by drag and ini xi drop right click in the Result list of the Existing Results Physical t
364. o optimize vehicle behavior including tire behavior using the potential of simulation software Because the tire properties determine to a great extent the vehicle behavior a tire model without proper tire data will be useless in most cases For full Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 9 MF Datasets and MF Tool A 9 1 A 9 2 optimization purposes the engineer requires the availability of datasets under a large range of conditions Tire Measurements Tire characteristics can be well described by the Magic Formula tire model The formulae are specified by a set of Magic Formula parameters that represent the characteristics in a compact form The parameters depend on the type of the tire and the road conditions and can be obtained from outdoor and or laboratory tests Calculation of Magic Formula Parameters Calculation of parameters from the measurement data is performed with regression techniques also known as parameter fitting ref 8 In sucha so called fitting procedure the results from measurements under pure slip conditions have to be used first to determine the Magic Formula parameters for side force self aligning torque and longitudinal force and in a second step the parameters for combined slip conditions see Figure A 17 The pure cornering measurements must include the influence of camber The parameters for transient cornering and braking are based on the steady state pure cornering and braking
365. oad state at different times in a transient simulation The Delay can then be set equal to the time where each load case is active and the same function can then be applied to each load case to obtain a smooth transition from one load case to the next Load Amplitude You can either enter a constant value or select a Function or Time history input file from the pull down menu This value or function will then be used as a scaling of the reduced load vector associated with this load case in the dynamics simulation CoG tab On this tab you can edit the position of the centre of gravity for a Generic Part You can also enter the orientation of the principal axis of inertia to be used as the reference for the inertias entered on the Mass tab Part Origin CoG Mass Stiffness Advanced Center of Gravity m Principal Axes of Inertia Reference CS Coordinate type Reference CS Coordinate type lu Link 7 REDE lt 1 Link MIN EuleiZYX as X Y Z z Rot Deg RotY Deg RotZ Deg 0 080933712 t 0 080933712 fos fo 0 0 0 0 0 Condense out Center of Gravity DOFs 9 Q This toggle enables the elimination of the DOFs associated with the centre of gravity in the dynamics simulation It is used to remove potential artificial internal vibrations in the Generic Part and thus increase the numerical stability of the model Fedem Release 5 0 User s Guide 4 11 4 Mechanism Elements 4 1 Links 4 12 Mass
366. oading FE Data CAUTION If you do not save a new model still named untitled fmmbefore you open another model or Exit Fedem all solver results associated with this model will be deleted if any This also includes the results of any Link reductions performed unless link repositories were used see Section 4 1 5 Using link repositories Indication on whether a Save is needed Fedem R4 2 Loader fmm When the current model has been changed PEINT y File Edit View Tools Mechanism compared to the previously saved version ITE oe Fedem will indicate this with an asterisk after the model file name in the title bar of the main window Only if this asterisk is present you will be asked if you first want to save the current model when you Open another model create a New model or Exit 2 8 3 Starting a new model You can at any time start modelling on a completely new model in the C current Fedem session by choosing New from the File menu or by clicking the new file icon in the toolbar This is equivalent to exiting the current Fedem session and then starting a new one see Section 2 4 Starting Fedem except that the new model now by default will be located in the same directory as the current model NOTE If the current model has been modified after the last Save you will be asked whether you want to save those changes before starting on the new model 2 9 Loading and unloading FE Data When a model
367. objects _ Dedpo Summary Origin Rz Sy aT U Raz Free 0 0 m Friction eo Noe m 4 Z translation DOF Description an optional user supplied name or identifying remarks Properties editable attributes specific to the selected object NOTE The description field may contain any ASCII character except for the character which is reserved for text string delimiters in the model file NOTE The description field is also used to activate beta features see Appendix F Beta feature documentation CAUTION After editing a value in the Property Editor by typing you must press the Enter key to apply the change Property menus Many mechanism items have internal properties that can depend on the oo zi JI simulation time measurement of a system variable or some internal variable in the item in question The Property menus are used to set up such properties in a simple way These menus consists of an option menu that in some cases are editable and an edit button The menu contains references to other entities in your model that can be used as v zi input for the property in question A I Driving Torque Function 1 non linear spring characteristic e g a pH mE force displacement curve will be listed in the stiffness property menu of an axial spring functions and control outputs will be listed in the magnitude property menu of a load et
368. obtained by travelling over the basic curve with a two point tire road interface The distance between the two points shift is slightly smaller than the contact length of the tire The effective plane height is obtained from the average height at the edges of the contact patch The effective plane angle is the slope of the line through the two point tire road interface with respect to the horizontal Rigid Wheel response Agigip The length of the basic function App is The length or width of the basic function can be approximated by a calculated in accordance with Equation B 26 Ap The offset los of the basic functions occurs when a threshold value for the height is exceeded In general the dependency on the height resembles the Rigid Wheel response This is incorporated in the functions of Equation B 27 Nos Both the length of the basic function and the offset of the basic function are displayed as function of the obstacle height in Figure B 11 B 16 B Using the SWIFT Tyre Model B 3 Force Evaluation m T Figure B 11 Basic Function Length and Offset as Function of Obstacle Height 0 3 tyre radius 0 2 Length Offset Normalised geometry of basic function 1 Lea 0 0 02 0 04 0 06 0 08 Normalised obstacle height 1 tyre radius The next step in determining the effective input is made by taking two points and run over the
369. ocal coordinate axes depends thus on the location of the contact point along the cam curve Cam joint variables Cam joints display all the six DOFs as joint variables in the Property Editor panel but have some restrictions on the Constraint Type setting that is unique for cam joints The only legal settings are Free and Spring Damper The Fixed and Prescribed settings are not available because the cam joint uses a different formulation than the other joints The three main joint variables defined in the x y and z directions of the cam joint s local coordinate system are gt X position The distance from the contact point to the follower in the direction normal to the cam surface the thickness direction Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints TIP If no stiffness is assigned to the X translation DOF the whole cam joint will be completely ignored by the Dynamics Solver This might be used as a simple tool to toggle a cam joint on and off during testing and modeling of complex models The solver issues a warning when the X translation spring is missing Y position The distance from the contact point to the follower in the direction tangential to the cam surface and normal to the cam curve width direction gt Z position The distance along the cam curve from the first cam triad to the contact point the slider variable You are also allowed to Spring Damper constrain the rotational D
370. ocessing Results they can be viewed during the dynamics analysis Your graphs and 3D views can be dynamically updated to show the results from the mechanism as they are computed Graphs If graph views are displayed see Section 7 2 3 Showing a graph during the dynamics simulation each curve is continuously updated with values from the solution reflecting the progress of the dynamics analysis TIP A graph showing the number of iterations for each time step gives a good 6 indication of both the progress of the simulation and how quickly each time step converges to the specified tolerance Animations If a 3D animation is loaded see Loading animations in Section 7 3 1 during the dynamics simulation the 3D view of the model is continuously updated with the rigid body motion of the link reflecting the simulation results The model can also be examined rotated zoomed and so on during the animation TIP The rigid body animation is an effective and intuitive way to observe the progress of the simulation When the rigid body animation is displayed a progress bar also appears in the upper right corner of the Modeler window TIP A rigid body animation may be started automatically when the dynamics solver starts by enabling a toggle in the Dynamics Solver Setup see Output tab in Section 6 5 1 TIP Animations can be loaded and closed at any time during the simulation CAUTION With large models and long simulations the
371. odel You can chose to enter this property either as an absolute value using the nitial stress free length angle option or relative to the Length angle in model by selecting the nitial deflection option CAUTION If you introduce a spring prestress in this manner it will be accounted for in the very first iteration of the dynamics simulation and thus lead to a dynamic shock effect However when initial Static equilibrium analysis is switched on the prestress force is taken as a pure static load and the transient shock should be avoided NOTE The initial deflection is positive when it increases the spring length angle stress free length angle change You can select a function to change the stress free length angle of the spring during the simulation see Section 4 10 Functions The value of the function will be used as an addition to the initial stress free length angle defined above 4 40 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 7 Springs and Dampers 4 7 2 TIP You can introduce motion into your system by using this option to change the length of a very stiff spring However an alternative and probably better way for joint variables is to use the Prescribed constraint type see Joint variable properties in Section 4 4 2 In that case the stiff spring is avoided and the DOF is eliminated as an unknown from the system of equations In most cases this yields a more stable solution Spring propert
372. odel are created by a different method Normally you first need to select the position s needed to place the new element Then you sometimes need to orient the element properly and then you finally have to attach it See Section 3 5 Moving mechanism elements and Section 3 6 Attaching and detaching elements Ihe only exception to this is the links which are treated completely different Please have a look at Section 2 12 Using the CAD integration Section 4 1 1 Creating links by file import and Section 4 1 2 Creating links from hard points To create a mechanism element complete the following steps 1 Click the button for the item on the Mechanism Creation toolbar see Mechanism Creation toolbar in Section 3 2 2 Follow the instructions in the Guide panel while selecting one or more positions or related objects in the Modeler window Positions can also be entered by using the Interactive Odometer See Section 3 3 2 Interactive Odometer and 3D Point Marker 3 When you are satisfied with a selection click Done to confirm When all positions selections are completed The element is created using the selected position s A sticker is normally applied to the new object automatically to make it easy to rotate using Smart Move 4 Youcan then use Smart Move or some other means to adjust the object s orientation see Section 3 3 3 Stickers and Section 3 5 Moving mechanism elements 5 Asthelast operation you
373. odulus and the shear modulus through the expression nu E 2G 1 if that yields a value within the valid range Fedem Release 5 0 User s Guide D File Types and Usage p n AppendxD File Types and Usage This appendix describes the file types used by Fedem and explains which program module use which files Sections in this appendix address the following topics File types File usage for each program module Fedem Release 5 0 User s Guide D 1 D File Types and Usage D 1 File types D 1 File types Fedem uses three main types of files input intermediate and results files Fedem files have an ASCII text or Binary platform independent format a common tag syntax and use intuitive naming conventions D 1 1 Input files Fedem uses several types of input files to import FE models existing mechanism models and simulation data as listed in the following table Ext File type Data Format fmm Fedem Mechanism Model Mechanism Model ASCII file description t1 Fedem Technology Link file FE model data ASCII ftc Fedem Technology Cad file Cad geometry data ASCII nas Nastran Bulk Data File FE model data ASCII bdf 1m_ Fedem Link Model used by FE model data ASCII previous Fedem versions anf Ansysinput file FE model data ASCII cdb inp ABAQUS input file FE model data ASCII dac nCode DAC file Time history data Binary asc ASCI
374. of the curve selected and uses it on all the objects of the same type in the model It also automatically assigns a color to the curves depending on the ID number Fedem Release 5 0 User s Guide 7 5 7 Postprocessing Results 7 2 Graphs of the object The colors assigned will be black blue cyan where low ID numbers makes the curve get a blackish color wile higher numbers will turn the curve blue or cyan Normally it is only the object used for the y axis value that is cycled but if the curve being repeated uses the same object both for the x and y axis they are cycled together 7 23 0 Moving curves to a new graph To move curves from one graph to another simply select the curves and drag them to the new graph This is done by pressing and holding the left mouse button while the mouse cursor is above the curves to move then move the mouse to the target graph and release the mouse button 7 2 3 Showing a graph Manager Results list right click and select Show Graph on the shortcut menu or select Show Graph on the Result menu The selected graph views opens in the Workspace area displaying the graphs m To display graphs select one or more graphs or curves in the Model 7 2 4 Graph properties Now that you can create a graph and its curves you need to specify properties for the graph To display the properties in the Property Editor panel select the graph in the Model Manager Results list The properties for the grap
375. of your mechanism click the Top button Right To display the side view of your mechanism click the Right button Front To display the front view of your mechanism click the Front button Bottom To display the bottom view of your mechanism click the Bottom button Left To display the left side view of your mechanism click the Left button Back To display the back view of your mechanism click the Back view button Fedem Release 5 0 User s Guide 2 21 2 Learning the Basics 2 7 Visualizing the model 2 7 2 3D View controls Fedem provides several 3D viewing commands for use in the Modeler window The following commands can be accessed on the 3D View Control toolbar or View menu T Solid View To display all mechanism elements as solid shaded objects click the Solid View button This is on by default amp Line View To speed up graphic performance and display all mechanism elements as outlines click the Line View button Flat Colors e To render the model without shading click the Flat Colors button This is especially useful when viewing color plots This option is off by default iB Show Top Faces To distinguish the top and bottom faces of shell elements click the Show Top Faces button The top faces will then be rendered normally while the bottom faces will be rendered dark black If some of the links have the detail level set to Reduced Surface or Reduced Surface and Internals only
376. oint is obtained from a Ball Joint by entering the command CVJoint RZ lt float gt RY lt float gt in the description field of the selected Ball Joint The X axis of the master triad should be oriented along the rotation axis of the master shaft link The direction of the slave shaft rotation axis the X axis is determined by one or both of the optional additional commands RZ lt float gt RY lt float gt RZ gives direction of slave X axis relative to master X axis by a rotation about the Z axis of the master triad RY obtains the X axis from the master X axis by a rotation about the Y axis of the master triad Care should be exercised when applying both rotations to obtain the X axis of the slave shaft since the angles are Euler Z Y rotations It is recommended that the master triad is oriented such that one only needs to use RZ or RY to define the X axis of the slave link Fedem Release 5 0 User s Guide F Beta feature documentation F 1 Joints es NOTE The constant velocity joint has only two independent joint DOFs the Y and Z rotations Specifying a spring stiffness and or damping for the third DOF X rotation for this joint is therefore meaningless although that is possible in the property window Any spring damper property specified on this DOF will be silently ignored The same is true for initial conditions F 1 3 Rigid Joint The DOFs of the Rigid Joint can be released individually by entering on
377. om F Show all frames Spacing 2500 T Continous T Oycle Close Max 2 000e 008 Cose Legend text Displays information regarding the loaded animation Legend bar Indicates the color assigned to each contour value Time step information Displays the time and the time step number for the current frame along with a progress bar Play Panel This panel is used to control how the animation is run o0 000 Animation controls This window features options to control several aspects of the animation including the contour legend domain 7 4 1 Play panel The Play Panel shown below is displayed in the lower right corner of the Modeler window when an animation is loaded Reverse Play o o e Continous Speed slider you can adjust the speed of the Cvdl ycle Cios o Pause Play Q Forward Play Q Beginning Rewind by Frame OW ea as Q Forward by Frame Peal End F Q stop Play Show all frames animation by moving the slider to the right or Fedem Release 5 0 User s Guide 7 33 7 Postprocessing Results 7 4 Viewing animations 7 34 left You can also click the Real button to return the speed to real time NOTE At faster speeds Fedem may skip frames in order to maintain animation speed at the level you have specified show All Frames this option forces Fedem to show all the frames loaded ignoring t
378. on about the stress analysis See Section 6 6 Stress recovery analysis to setup and perform the stress analysis 6 1 4 Modeshape recovery A mode shape recovery analysis enables you to expand the system mode shapes calculated during the dynamics simulation These mode shapes can later be animated See Section 6 7 Mode shape recovery analysis to setup and perform the mode shape analysis 6 1 5 Strain rosette recovery Fedem enables you to recover strains and stresses from virtual strain gages which are defined in a separate file The results are similar to those from real strain gages See the Fedem R5 0 Theory Guide Section 9 5 Virtual strain gauges for more information about the strain rosette analysis See Section 6 8 Strain rosette analysis to setup and perform the strain rosette analysis 6 1 6 Strain coat recovery The strain coat recovery process calculates the stresses and strains on the strain coat elements in the model in a similar manner as in the strain rosette analysis This is primarily used as input for subsequent fatigue calculations See Section 6 9 Strain coat analysis to setup and perform the strain coat analysis 6 1 7 Duty cycle analysis Running a duty cycle analysis means summing up the damage done to any set of links from several load events or load cases The results obtained are summaries of the damage from the combination of all the events See Section 6 10 Duty cycle analysis to setup and perf
379. oncept uses a quarter sine function to describe the response of the tire to a step obstacle The length of the basic function corresponds to the lengthening effect and the swallowing effect is taken care of by using a two point contact Additionally the rolling radius variations that result from rolling over an obstacle is modelled A cleat obstacle is converted into an effective height and plane angle as shown in Figure B 9 Figure B 9 Effective Inputs effective plane height b effective plane angle c tyre rolling over an effective surfac The effective inputs plane height o and plane angle p are calculated B using the basic function or curve is demonstrated in Figure B 10 The basic function relates to the response of a rigid wheel and the parameters depend on the tire radius Rg and obstacle height h only Fedem Release 5 0 User s Guide B 15 B 3 Force Evaluation Figure B 10 Example for Effective Inputs with Basic Curve A c Yi oo Yz Su A 2 Yj 5 od A EE Yj 7 at Yip air a EE A aL ZA ZA yy Migs Ql E Vi Ps R yy z GZ a Yi Y e SEE Vy Yj WHY LLL B 26 B 27 B 28 a ES Tosio d4os2 grGrp Ptl 4 o Ro h gt Ios o q Af RIGID B Using the SWIFT Tyre Model The height of the sine wave is equal to the step height and the width is approximately equal to the width of the rigid wheel response The effective road surface is
380. one file per mode false VTFfile Name of VTF output file VTFoffset VTF result block id offset 0 VTFparts Number of parts in VTF file 0 write nodes Save results as nodal data false write vector Save results as vector data true Fedem Release 5 0 User s Guide E 15 E Command line options Ss E 6 Strain rosette recovery options fedem_gage E6 Strain rosette recovery options fedem gage Command line Ss option Description Default value binSize Bin size for stress cycle counting MPa 10 Bmat file Name of B matrix file Bramsize In core size MB of displacement recov 1 ery matrix lt 0 Use the same as in the reducer 0 Store full matrix in core consolemsg Output error messages to console false cwd Change working directory dac_sampleinc Sampling increment for dac output files 0 001 datacheck Do data check only exiting after data false input debug Debug print switch 0 deformation Save nodal deformations to results data false base eigfile Name of eigenvector file fao Read additional options from this file fatigue Perform damage calculation on the gage 0 stresses fco Read calculation options from this file flushinc Time between each database file flush 1 lt 0 0 Do not flush results database let the OS decide 0 0 Flush at each time step no external buffers gt 0 0 Flush at specifi
381. onia re a E meme 2 38 2412 License denial seee os tee t ete EEE EAN MES 2 38 2 11 3 License file server 0 cece cece cece cece ence meme 2 39 2 11 4 Managing license files servers 00 c eee e cece cent e 2 39 Using the CAD integration ccc cece cence een e en ennee 2 39 ZTT OVOrVIQW ce etes emt estes hx ERR Ve optan I sce mane Re Ecc tote 8 2 39 2 12 2 Model association sisse mee 2 40 2 12 3 How parts and subassemblies translate to Fedem links 2 41 2 12 4 Process COMMUNICATION cece cece eee emen 2 41 2 12 5 Commands in CAD system The Fedem menu cece eens 2 42 2 12 6 Commands in Fedem cece cece cence ene eee 2 43 Mechanism Modeling Basic assembling techniques cece eee eee cece eee erene 3 2 Mechanism modeling environment e cece cece cence eee 3 2 3 2 1 Modeler window 0 0 ccc cece cee n eee mme hen 3 3 3 2 2 Modeling toolbars 0 cece cece cece cent mme 3 3 Mechanism modeling tools else 3 4 3 3 1 Reference Plane ccc cece cece cence eee hene memes een 3 4 3 3 2 Interactive Odometer and 3D Point Marker ece cece eeees 3 5 3 3 3 Stickers ovp E ATTEN Aa od eee VAN Ted La ee 3 6 Creating mechanism elements lees 3 7 3 4 1 Selecting position and orientation cece cece cece eee ee eens 3 8 Fedem Release 5 0 User s Guide V 3 5 3 6
382. opens the associated Fedem model in Fedem If no associated model exists you are prompted whether you want to create a new one Update Fedem Model M This command opens the associated Fedem model and updates it with the changes from the CAD assembly Geometry mass properties and positions of all the links are then updated New Fedem Links will be created for new parts and subassemblies while parts and subassemblies that have been removed will need some more attention Parts or subassemblies that have been moved from one position in the assembly hierarchy to another will not be recognized as moved It will rather appear as if they are deleted and that some completely new parts subassemblies have appeared This is somewhat inconvenient regarding all entities in Fedem that could have been associated attached to the links To make updating a bit more convenient in such cases an Update Wizard is used to allow you to reassociate the Links in Fedem that no longer have a valid reference to parts in the CAD assembly The Update Wizard pops up when Fedem discovers that some Links have an invalid reference to the CAD assembly It steps through all the Links that have lost their referenced CAD part or subassembly and lets the user choose to either delete it or merge all its connections onto a different link List associated Fedem Models This command lists all the configurations in the assembly along with the file name of any associated
383. opology panel When an object in the model is selected the ID and Topology panel displays information related Revolute joint ne H Slave Triad 8 to the object as described below Ep Master ad 1 A Joint springs If multiple items are selected only tbe Jointspring 1 the item selected last is displayed Qi Joint dampers LA Joint damper 1 item Type the type of the Joint loads selected object for example 5 Plotted by revolute joint gear or spring Curve 1 angle i Curve 2 welocity 2 10 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 5 Touring the interface ID Number a unique integer that distinguishes one item of the same type from another Topology View a list that displays the mechanism objects related or connected to the selected item TIP The Plotted by branch in the Topology View lists all curves that plot result quantities from the selected structural object ID numbers are assigned automatically to new objects in numerical order If you delete an object such as a ball joint with ID Number 3 this number is free and the next ball joint created is then assigned ID Number 3 Topology View and browsing Most mechanism elements are related to other objects for example joints consists of triads that are connected to links and sensors are measuring variables from other mechanism elements These relations are shown by the Topology view in a hierarchical fashion indic
384. optimal performance Contact length for load variations VERTICAL VERTICAL STIFFNESS C Flat Planksee Equation B 22 Vertical stiffness vertical belt frequency VERTICAL DAMPING MF Tyre BREFF MF Tyre DREFF MF Tyre FREFF MF Tyre FNOMIN Fzo see Equation B 2 defined value for measurement programme Tire load rating Q REO Creo see Equation B 19 Free tire and effec tive tire radius Q V1 qv1 see Equation B 18 Tire growth due to speed Q_V2 v2 see Equation B 21 Speed effect on vertical stiffness Fedem Release 5 0 User s Guide B 25 B Using the SWIFT Tyre Model B 26 B 4 Tire Model Parameters Table B 8 Definition of Parameters in Tire Property File Continued Tire parameter mae al Notes ire pa notation Tire characteristic if applicable Q FZ2 Grz2 See Equation B 21 Progessiveness of vertical load for deflection Q FCX GFcx See Equation B 21 Decrease in verti cal stiffness due to brake slip force Q FCY Grcy See Equation B 21 Decrease in verti cal stiffness due to side slip force LONG SLIP RANGE MF Tyre SLIP ANGLE RANGE MF Tyre INCLINATION ANGLE RANGE MF Tyre VERTICAL FORCE RANGE MF Tyre SCALING COEFFICIENTS MF Tyre LONGITUDINAL COEFFICIENTS MF Tyre OVERTURNING COEFFICIENTS MF Tyre LATERAL COEFFICIENTS MF Tyre ROLLING COEFFICIENTS MF Tyre ALIGNING COEFFICIENTS MF Tyr
385. orm the duty cycle analysis 6 4 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 2 Solver tools 6 2 6 2 1 6 2 2 Solver tools Several dialogs and tools can be utilized to control the calculation processes in Fedem In this section we describe those applying to all the solver processes Solvers Toolbar The Solvers toolbar shown below contains the commands to set up and start each of Fedem s mechanism analyses including the pre and postprocessing of individual mechanism links The toolbar is organized from left to right in the order of logical task performance i e model reduction is performed first then the dynamics simulation stress recovery and so on lbo t Be Be Be B The setup commands Dynamics Solver Setup Stress Recovery Setup Mode Shape Recovery Setup Strain Rosette Recovery Setup Strain Coat Recovery Setup Duty Cycle Setup and Additional Solver Options enable management of all analysis options Each of the Solver commands are described in the following sections of this chapter TIP To access all commands on the Solvers toolbar click and hold down those buttons with an arrow W next to the icon NOTE You can also access all Solver tools from the Solve menu TIP Once you have set up the parameters for each of the solvers as described later in this chapter you can click the Solve All button on the Solvers toolbar or Solve menu to execute all analyses in consecutive order
386. ormance Some improvement may be obtained by setting the Simulink time step fixed but care should be taken not to deteriorate the accuracy 5 5 5 Limitations In general the co simulation is restricted to non discrete blocks with scalar input and outputs In addition the method fails for elements depending on older values than those from the previous step This is the case for the Transport Delay Derivative Backlash and Relay blocks Simulink elements that have been tested and found to work properly are summarized in the table below Group Elements From Workspace Clock Constant Step Ramp Sources Sine Wave Pulse Generator Signal Generator Chirp Signal Sinks To Workspace Continuous Integrator State Space Transfer Fcn Drei Coulomb amp Viscous Friction DeadZone Quantizer Saturation Discrete Zero Order Hold Fedem Release 5 0 User s Guide 5 13 5 Control System Modeling 5 5 External control systems uu Group Elements Abs Gain Math Function exp log 10 log10 magnitude square sqrt pow reciprocal rem Math mod MinMax min max Product Rounding Operations Function floor ceil round fix Sign Sum Trigonometric Function sin cos tan asin acos atan sinh cosh tanh asinh acosh atanh Signal Routing Switch Refer to the latest Release Notes for continuous and discontinuous Simulink blocks that do not work 5 14 Fedem Release 5 0 User s G
387. otes at any time also when you have results Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 9 Model preferences 3 9 1 3 9 2 3 9 3 Model database units All modeling in Fedem is unit independent However some external interfaces like tire and road uses SI units in their calculations When modeling in other units than SI you will need to change the model database units Do this by selecting the model database units corresponding to your model The chosen units are then used to properly scale calculated data before communicating with external modules that require a specific unit set like tire road data files TIP You can add your own modeling units by editing the file units fed in any ASCII editor This file is located in the Fedem installation directory Modeling tolerance The modeling tolerance is a tolerance that controls how strict Fedem enforces that triads and their corresponding FE nodes are coincident This tolerance needs to be strict because an offset will introduce an error and inconsistence in the numerical model which might have serious impact on the reliability of the results The seriousness is however depending on the size of the offset compared to the size of the FE models in question and the overall size of the model If you experience problems when trying to attach triads to a link you might need to increase the modeling tolerance The default tolerance is set to 1e 4 of the length un
388. ound The Visibility slider controls the distance at which the model is completely hidden in the Fog TIP You can create the following effects with the Fog option Tocreate the effect of a foggy day set the Modeler background color to light gray Red 180 Green 180 Blue 180 enable the Fog option and adjust the Visibility slider until the model almost fades into the background Tocreate the effect of an underwater scene set the Modeler background color to sea green Red 20 Green 125 Blue 130 enable the Fog option and adjust the Visibility slider until the model nearly fades into the background Simple Transparency is a dithering algorithm used to speed graphic performance when displaying transparent objects in your model The effects of this option depend on the type of graphics card you have Fedem Release 5 0 User s Guide 2 25 2 Learning the Basics 2 7 Visualizing the model Anti Aliasing enables disables line smoothing for symbols TIP If Anti Aliasing does not function properly try enabling the Simple Transparency option NOTE Graphics cards do not all have the same optimal settings In general disabling the Fog and Anti Aliasing options and turning on Simple Transparency gives the best performance but with some systems the performance gain is insignificant 2 7 5 Item Appearance The tem Appearance command can be used to change the level of detail and the appearance of individual links and the
389. ound by their master triads Two or more slave triads can not be attached to the same FE node Master triads or triads where the triad directions is referenced must be aligned before they can be attached to the same FE node NOTE When several elements are attached to the same node the triads in those elements are merged into the triad already attached This resulting triad is then shared by all the attached elements The Redundant triads are removed 3 20 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 6 Attaching and detaching elements a NOTE When a triad is attached to a FE model at the position of a slave FE node Fedem will automatically add a 6 DOF node a spring and a mass element to the FE model at that point The triad is then attached to the new 6 DOF node instead of the slave node to overcome limitations in the mathematical methods used The spring stiffness and mass is set automatically by the Link Reducer to a very high stiffness and avery low mass compared to the actual model in question However if the link is completely rigid e g it consists of a single RGD element the value 2e11 is used for stiffness and no mass is added See also the Fedem R5 0 Theory Guide Sections A 10 BUSH and A 12 CMASS 3 6 5 Detaching To detach mechanism elements from your model complete the following steps 1 Click the Detach button on the Mechanism Tools toolbar or select Lut nt from the Mechanism men
390. ouple Nm My braking driving moment Nm Mz aligning moment Nm References 1 H J Unrau J Zamow TYDEX Format Description and Reference Manual Release 1 1 Initiated by the International Tire Working Group July 1995 A Riedel Standard Tire Interface Release 1 2 Initiated by the Tire Workgroup June 1995 E Bakker L Nyborg H B Pacejka Tire Modelling for Use in Vehicle Dynamics Studies SAE paper 870421 1987 E Bakker H B Pacejka L Lidner A New Tire Model with an Application in Vehicle Dynamics Studies SAE paper 890087 1989 H B Pacejka E Bakker The Magic Formula Tire Model Proceedings 1 International Collo quium on Tire Models for Vehicle Dynamics Analysis Swets amp Zeitlinger B V Amsterdam Lisse 1993 P Bayle J F Forissier S Lafon Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 11 References se A New Tire Model for Vehicle Dynamics Simulations Combined Cor nering and Braking Driving Manoeuvres Michelin France 1990 7 H B Pacejka The Tire as a Vehicle Component XXVI FSITA Congress Prague June 16 23 1996 8 J J M van Oosten E Bakker Determination of Magic Formula Tire Model Parameters Proceedings 1 International Colloquium on Tire Models for Vehicle Dynamics Analysis Swets amp Zeitlinger B V Amsterdam Lisse 1993 9 J J M van Oosten H J Unrau G Riedel E Bakker TYDEX Workshop Standardization of Data Exchange in Tyre Testing and Tyre
391. ponent mode numbers see Reduction Options tab in Section 4 1 4 or the free free mode numbers for the reduced link depending on the selected mode type in the first pull down list Scale You can specify a scale factor to exaggerate the shapes during the animation NOTE The default Scale setting 1 0 implies that the maximum amplitude of the shape is equal to the length scale used to model the mechanism Therefore if the length span of the model is not 1 0 it is necessary to adjust the Scale option in order to obtain an appropriate deformation scale Frame Generation These options allow you to set the number of animation frames and the duration of the animation Frames per cycle Entering a higher value increases the continuity of the animated motion Length You can specify either a Time No of cycles or Until 96 damped to limit the duration of the animation These fields are available only for System modes For Component modes of link and Free free modes of reduced link the duration of the animation will always be equal one full cycle NOTE The Until Damped option is relevant only if a damped eigenmode solution was performed see Eigenmode tab in Section 6 5 1 NOTE When animating eigenmode shapes the time that runs in the upper right corner of the modeler window is in the range 0 n T where T is the period 1 eigen frequency and n is the number of cycles that are animated usually n 1 for fre
392. ponse rs ASCII results res Fedem Stress stress recovery Solver input file si Solver control files co fop fao Matrix files recovery component modes mx Data structure file sm FE link file t 1 Solver result files fxs Result files s ASCII results res D 4 Fedem Release 5 0 User s Guide D File Types and Usage D 2 File usage for each program module Fedem application Fedem Modes eigenmode recovery Uses these file types Solver input file s1 Solver control files co fop fao Matrix files recovery component modes mx Data structure file sm FE link file t 1 Solver result files rs Creates these file types Result files s ASCII results res Fedem Gage strain rosette recovery Solver input files 1 Solver control files co fop fao Rosette input files ros dat Matrix files recovery component modes mx Data structure file sm FE link file t 1 Solver results files s Result files frs ASCII results res asc DAC time history files dac Fedem FPP strain coat recovery Solver input file fsi Solver control files co fop fao Matrix files recovery component modes mx Data structure file sm FE link file t 1 Solver result files 175 S N curve definition file s
393. pplication of the Additional Boundary Conditions specified for triads see Cancel Section 4 3 3 Triad properties You can enable disable computation of damped eigenmodes by accounting for structural damping see the Fedem R5 0 Theory Guide Section 9 6 2 Damped eigenvalue problem CAUTION Computation of damped eigenmodes takes considerably longer time than computing the undamped modes You can enable disable the Geometric Stiffness Contribution in the eigenvalue analyses see the similar option in the Integration tab If the mechanism contains structural members that experience large tensile or compression forces at certain time steps the geometric stiffness contribution may have a significant effect on the accuracy on the computed eigenvalues at those time steps Fedem Release 5 0 User s Guide 6 23 6 Mechanism Analysis 6 5 Dynamics analysis 6 24 Initial Equilibrium tab If during modeling your model is not positioned at its static equilibrium position it is recommended that you perform the nitial Equilibrium analysis to move the mechanism to a resting position before simulating the dynamics You can enable this option to Tum perform initial equilibrium iterations Time Integration Tolerances Eigenmode Perform equilibrium iterations at initial position You can adjust the iteration tolerance and the step size factor for the initial equilibrium iterations You can enable disable the G
394. pplication where they are present Guy T M e g a spreadsheet or a text editor poc On win32 based systems they have Ea Cays to be copied to the clip board by poi 1 1 1 1 yy Pressing Ctrl C The numbers are x then inserted into the polyline function by clicking the list and pressing Ctrl V Refer to Section 4 10 4 Extrapolation to learn about the extrapolation of a polyline function Polyline from file This function is similar to the polyline function except that the points now are read from a file The file format can either be single or multi channel ASCII asc txt DAC dac or RPCIII time history rsp drv tim For multi channel ASCII and RPCIII files the channel to read is chosen by pressing the Select button Additional parameters for scaling and vertical shift of the function may also be specified in the Property Editor panel of this function type shown below r Function Type 4 Parameters Fie Relerence T Argument Channel E set E 1 CilOut scale ro DOF Vertical shift after scale Var x Parameter Help Preview Poly line from file Shift function to zero out start value Additional shift o 0 For abscissa value v the returned ordinate f v of the polyline from file function is v Xi fv vez Em Oje1 y s k sX lt VSX4 X ypielln itl i s scale k vertical s
395. quation B 7 in which mg is the mass of the tire 2 I mg Ro B 7 The normalized variables that occur in the equations are denoted by an overbar Table B 1 Forces and Moments Symbol Description Units nens Fox Longitudinal belt force N Foy Lateral belt force N Foz Vertical belt force N Fgrv Gravity force N Fi Longitudinal residual force N Fry Lateral residual force N F Normalized longitudinal force Fzo F Normalized lateral force Fz0 F Normalized vertical force Fro Fz Vertical axle load N Fzo Nominal tire load N B Using the SWIFT Tyre Model B 2 Notation Table B 1 Forces and Moments Symbol Description Units be aaa Mp x Camber belt torque Nm Mpy Wind up belt torque Nm Mpz Yaw belt torque Nm Mi Yaw residual torque Nm Table B 2 Radii Symbol Description Units pet Dro Speed radius increase RI Loaded tire radius m Ro Nominal tire radius m Re Effective rolling radius m Rw Free tire radius m Table B 3 Inertia Symbol Description Units eee Mo Tire mass kg i m Normalized belt mass mo lo Reference moment of inertia kgm Table B 4 General Coefficients Symbol Description Units Renee Cgrv Gravity constant E Gbvx Correction coefficient radial belt stiff ness
396. quickly it is convenient to use the arrow B keys to navigate between the drop down menus and the N key Not Loaded or L key Loaded to set the status 2 9 2 Skipping FE Data when opening a model file When opening a big model for inspection or to start a calculation process it is sometimes convenient to override the FE Data Settings and skip the FE models completely In that way you can open a model containing extremely large links in a few seconds without using any significant amount of memory To do this toggle the Skip FE Data toggle in the File Open dialog when opening a model file or use the noFEData command line option together with modelfilename when starting Fedem The model will then be loaded with all the links unloaded To load the links open the FE Data Settings dialog This dialog now shows the status on the links last time you saved your model If you simply press OK or Apply those settings will be applied and the links marked as Loaded will be loaded 2 9 5 Modeling with unloaded links An unloaded link can generally be used as any link while modeling but there are some restrictions When selecting points on the link the points will not snap to the closest node because the node information is not loaded The only points on the link that are available for selecting and modeling are the external nodes represented by the triads Fedem Release 5 0 User s Guide 2 33 2 Learning the Basics 2 10 Printing
397. r If only singularities of the first kind are detected the reduction process completes successfully and it should be safe to use this link in a dynamics simulation However if one or more singularities of the second kind are detected the reduction is aborted with no results and the FE model has to be manually fixed before a new attempt is made CAUTION If more than one singularity of the second kind are detected there is a possibility that some of them except the first one are fictitious On the other hand there is also a possibility that not all singularities are detected Thus after having fixed all the reported singularities manually other singularities may be revealed in the next run This behavior is due to the insertion of a small value on the diagonal which actually changes the mechanical property of the FE model It is possible to switch off the above treatment of singularities during model reduction This is done by specifying singularityHandler 0 as an additional option to the Link Reducer see Section 6 2 3 Additional solver options Only the first occurring singularity regardless of its kind will then be printed to the Output List and res file and then the reduction process will abort This corresponds to the behavior in Fedem R3 1 and earlier Singularity tolerance The criterion used to determine if a stiffness or mass matrix is singular during the reduction is specified through a threshold value in the Property
398. r a detailed description see the Fedem R5 0 Theory Guide Section 8 4 5 General transfer functions Real Pole block h ias The Real Pole block is a first order transfer function The Real Pole block has a pole positioned on the real negative axis in the s plane H Complex Conjugate Pole block T The Complex Conjugate Pole block is described by a second order differential equation s First Order Transfer Function block iud The First Order Transfer Function block is described in detail in the Fedem R5 0 Theory Guide see First order element in Section 8 4 5 Second Order Transfer Function block The Second Order Transfer Function block is described in detail in the Fedem R5 0 Theory Guide see Second order element in Section 8 4 5 5 4 Building control modules The control module is fully defined when all blocks are connected and the inputs and outputs are attached to sensors and actuators in the mechanism model Fedem Release 5 0 User s Guide 5 7 5 Control System Modeling 5 4 Building control modules 5 4 1 5 4 2 5 4 3 5 8 Setting Grid and Snap ioj x You can manipulate the Grid and Snap vie settings in the Control Editor by selecting Grid size the Control Editor Grid Snap button from the x 1 00 Tools menu or the Control Tools toolbar The v 1 00 Grid and Snap dialog window is displayed shown at right IV Snap On Off NOTE Grid and Snap options are applicable only for Snap di
399. r a complete circle TIP You can use the same cam triads in several different cam joints making it possible to constrain several follower triads to the same cam surface An example cam joint is shown to the right Slave follower triad 2 Master cam triads represented by the sets of x y and z axes extending from the curve Cam curve represented by the curve Creating cam joints The cam curve is defined by circular arcs and straight lines Each three point arc is defined by three triads If the triads are located on a straight line a straight line will be defined circular arc with zero curvature To create a cam joint complete the following steps Click the cam joint icon Select a position for a new follower triad or select an existing triad Confirm by pressing Done If an existing triad was selected this triad will become the follower triad otherwise a new triad is created 4 Select a position for the first master or select an existing triad You can also select an existing cam curve 5 Confirm by pressing Done If an existing triad was selected this triad will become the first cam triad otherwise a new triad is created If an existing cam curve was selected the new cam joint is complete and the selected cam surface will be used by the new follower triad Fedem Release 5 0 User s Guide 4 33 4 Mechanism Elements 4 4 Joints 4 34 6 Repeat steps 4 and 5 until a sufficient number of
400. r convergence toler 0 ance tolResRot Max residual torque tolerance g tolResTra Max residual force tolerance 0 tolUpdateFactor Convergence criterion for continuing 0 matrix updates tolVelGen Max generalized velocity tolerance 0 tolVelNorm Velocity vector convergence tolerance 0 tolVelRot Max angular velocity tolerance 0 tolVelTra Max velocity tolerance 0 version Print out program version false VTFfile Name of VTF output file For all the convergence tolerance options its value is interpreted as follows 0 This tolerance is ignored gt 0 This tolerance is in a set of tests where all must be satisfied lt 0 This tolerance is in a set of tests where only one must be satisfied using the absolute value as the actual tolerance value Fedem Release 5 0 User s Guide E Command line options E 4 Stress recovery options fedem_stress e E 4 Stress recovery options fedem stress eRe Description Default value Bmatfile Name of B matrix file Bramsize In core size MB of displacement recov 1 ery matrix lt 0 Use the same as in the reducer 0 Store full matrix in core consolemsg Output error messages to console false cwd Change working directory datacheck Do data check only exiting after data false input debug Debug print switch 0 deformation Save deformations to results database false dou
401. r s Guide 3 9 3 Mechanism Modeling 3 5 Moving mechanism elements 35 Moving mechanism elements Fedem provides several commands and tools for moving parts of your model The Smart Move Align CS Align rotations and Move To Center are useful commands while the Origin property that several mechanism objects share can be used to access the position and orientation of a single component directly 3 5 1 Smart Move Smart Move is an integral part of 3D modeling in Fedem It is a sophisticated way to position and orient mechanism entities such as links triads joints springs dampers and so on The command enables you to move or orient an object or a group of objects according to the selection s current movability see below During a move Smart Move also automatically adds a movability constraint called a sticker see Section 3 3 3 Stickers Movability The movability of an object or a group of objects is determined by examining not only the stickers that are applied to the selection but also the joints between the selected object group and other objects Each joint or sticker that constrains the group reduces its movability The following symbols represent the six types of motion allowed when using the Smart Move command gt Free when an object without stickers or attached joints is moved with the Smart Move command it can move in translation in any direction The symbol for free movement is depicted in the Modeler as show
402. r triad The cube represents the joint itself 4 28 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints Free joint E The free joint has six joint variables The free joint can thus be used to a T introduce any type of mechanism motion constraint by setting the constraint type of each joint variable to fit your needs The symbol for a free joint is displayed in the Modeler window as shown to the right The coordinate system in the lower left straight arrows represents the master triad The rounded arrows together with the line between the two X coordinate systems represent the joint itself The coordinate system in the upper right with double arrows 4 represents the slave triad You can add friction to one Friction of the free joint DOFs by N selecting one from the list Joint DOF Rx of frictions in your model in the Friction pull down list The list of selectable frictions depends on whether you have selected a translational or a rotational dof in the Joint DOF pull down list The effective normal load in the friction is then computed from the two joint DOFs that are orthogonal to the selected DOF See also Section 4 6 Frictions and the Fedem R5 0 Theory Guide Section 6 5 Joint Friction Moving point to point joints The point to point joint types have three parts that either can be moved independently or as a whole To turn on and off this behavior a g
403. racteristics Figure B 3 shows the out of plane deflection of the tire and related specifications Fedem Release 5 0 User s Guide B 9 B Using the SWIFT Tyre Model B 3 Force Evaluation B 3 4 Figure B 3 Out of Plane Deflection of the Tire rigid tyre ring 6 DOF wheel plane axle and rim sidewall stiffness S damping elements E E lt residual stiffnesses 4 tyre road interface The out of plane stiffness is not dependent on speed and or load The lateral force acting on the wheel carrier is given in Equation B 15 Epy Cy PbyF zo 2Ky pp ks B 15 Belt camber torque is calculated using Equation B 16 and the yaw torque is calculated using Equation B 17 My Xx PbyCro 2K y Poyk o B 16 My Cy PbwCro 2K py Poyk o B 17 Vertical Force Characteristics The overall vertical tire force is the tire force that results from a steady state vertical deflection of the tire As the vertical tire belt stiffness is modelled with the Rigid Ring model a residual spring is introduced in order to achieve the overall vertical force characteristic of the tire see Figure B 5 Changes in vertical force due to slip forces are incorporated in the vertical force calculation The vertical tire force is a function of deflection and speed The tire deflection is used for the overall vertical force and is the difference between the free tire radius Rg and the loaded tire radius R The free tire B U
404. rainflow analysis and fatigue calculations for the selected element group Standard Select the fatigue standard to use for in the fatigue calculations Q S N curve Select an S N curve from the selected fatigue standard Stress concentration factor The computed stresses are scaled by this value before they are used in the fatigue calculation TIP The S N curve standards available in the pull down menu are defined in the file sn curves fsn located in the installation directory of Fedem The syntax of the S N curve definitions is description in the header of this file and it is possible to add your own S N curve definitions to that file For details on how damage is calculated from a given time history response see the Fedem R5 0 Theory Guide Fedem Release 5 0 User s Guide 4 17 4 Mechanism Elements 4 3 1 4 3 2 4 3 Triads Triads To construct a working mechanism links are connected to each other using elements such as joints springs dampers loads and so on Fedem uses a modeling object called a triad to make these connections The triad defines a set of three mutually perpendicular coordinate axes originating from the connection point Triads enable links to be connected to other mechanism elements using the links FE nodes as connection points When links are joined together in your model the connection points are retained after the model reduction process as external FE nodes see the Fedem R5 0 Theory
405. rctan tan a 2 x sgn a A 81 y 2 Kx 2 Q eq Z arctan tan a 2 X sgn a A 82 Table A 14 Aligning Torque Combined Slip Name used in tire m Name property file Explanation Ssz1 SSZ1 Nominal value of s RO effect of Fx on Mz S z2 SSZ2 Variation of distance s RO with Fy Fznom Ssz3 SSZ3 Variation of distance s RO with camber Ssz4 SSZ4 Variation of distance s RO with load and camber Formula Overturning Moment M gt R d F ldsyi j Aymet 745 5 jet dsx3 FF Aug A 83 A 28 Fedem Release 5 0 User s Guide A Using the MF Tyre Model A 6 Steady State Magic Formula Table A 15 Overturning Coefficients Name used in tire Name property file Explanation qdsx1 QSX1 Lateral force induced overturning couple Gs QSX2 Camber induced overturning couple qdsx3 QSX3 Fy induced overturning couple Formula Rolling Resistance Torque 4 M R F tasyi asy2Fx F0 a Isy3 Vx Vives t Isyg V Vref j If qsy and qsy2 are both zero then the following is true as in MF Tyre 5 0 M Ro Sy b K Six A 85 Table A 16 Rolling Coefficients A 84 Name used in tire Name property file Explanation dsy1 OSY1 Rolling resistance torque coefficient dsy2 QSY2 Rolling resistance torque depending on Fx Asy3 OSY3 Rolling resistance torque depending on speed Asya OSYA Rolling resistance torque depending on speed 4 Vref LONGVL Measurement speed Fe
406. rdinate system will be displayed in red Press Done to confirm the selection and execute the move TIP The Align commands can be used to align objects to local FE coordinate systems if present The visibility of local coordinate systems can be toggled using the General Appearance dialog See Section 2 7 4 General Appearance 3 5 3 Move To Center Move To Center is a useful tool if you want to position an object at the es center of some geometry The object will move to the center of a circle you define or somewhere along its axis The new orientation of the object aligns with the circle The x axis is defined by the center and the first point defining the circle the z axis is perpendicular to the circle 3 12 Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 5 Moving mechanism elements 3 5 4 Performing a Move To Center To move an object or group of objects using the Move To Center command complete the following steps 1 Click the Move To Center button in the Mechanism Tools toolbar It is located under the Smart Move icon 2 Select the objects to move by picking them in the model view Press Done to confirm the selection TIP Several objects can be selected by pressing and holding the Ctrl key while selecting objects To change the last selected object only release the Ctrl key and select until you hit the right object To remove several of the last selected objects from the selection release the Ctrl key
407. rdinates for a curve complete the following steps 1 In the Model Manager Results list select the curve you want to edit Its properties are displayed in the Property Editor 2 Inthe Property Editor click the Edit button for the X Axis or right click on a curve in the Model Manager Results list and select Edit X Axis or Edit Y Axis The Results Database Selector window shown at right is displayed 3 Select a mechanism element from the Existing Results list or the Modeler window NOTE If the mechanism analysis have been performed variables for the selected element are listed in the Existing Results list If you have not yet performed an analysis variables are listed in the Possible Results list 4 Select a variable to be used as the x coordinates from either the New Curve Y Axis Definition loj xj Existing Results i Physical time i Time step number Joints Triads Position matrix Velocity Angular velocity Acceleration Angular acceleration Force Moment H Local coordinates 2 3 4 5 6 7 8 3 amp amp 10 zi Possible Results B Position matrix Velocity Angular velocity Acceleration Angular acceleration Force j Moment Local coordinates OK Apply Cancel Existing Results or Possible Results lists and click OK to close the panel or Apply to continue variable selection CAUTION Some of the var
408. rence coordinate system of the link and for using centripetal force correction for the selected link It also contains a toggle and field for specification of an external result file for import of residual stresses in the Stress and Strain Coat Recovery processes Part Origin CoG Mass Stiffness Advanced Positioning algorithm for co rotated reference coordinate system Model default 0 Centripital force correction Model default e Import residual stresses from external file External result file The options for the co rotated reference coordinate system are Model default The global setting defined in the Integration tab of the Dynamics Solver Setup is used see Section 6 5 1 Dynamics Solver Setup Fedem Release 5 0 User s Guide 4 13 4 Mechanism Elements 4 1 Links Max triangle with unit offset when necessary This is the original algorithm the only one available in Fedem R3 1 1 and earlier Maxtriangle with link scaled offset when necessary The same as above but with adjustments of the offset to better fit the link size Mass based nodal average Algorithm based on equilibrium of a rigid shadow element with averaged stiffnesses at the triads See the Fedem R5 0 Theory Guide Section 4 1 Superelement local coordinate system for a detailed description of these algorithms The options for the centripetal force correction are Model default The
409. resent 7 3 1 Managing animations Creating animations You can create as many animations as you like It is recommended that you provide descriptive names for your animations Stress Strain or Eigenmodes and so on as the description is used in the Model Manager Results list to distinguish between the animations To create an animation select Animation on the Result menu or right click in the Model Manager Results list select Create then Animation on the shortcut menu Loading animations Once the animation is created you can show it in the Modeler window by performing the following steps EJ 1 To open the Modeler window click the Show Modeler button on the Windows toolbar or Windows menu The Modeler window opens in the Workspace area 2 Select the animation in the Model Manager Results list Click the Load Animation button in the Property Editor panel or right click the animation in the Results list and select Load Animation on the shortcut menu The animation is loaded and both the Contour Legend and Play Panel are displayed in the Modeler window see Section 7 4 1 Play panel 7 22 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 3 Animations es TIP Changes to animations cannot be updated instantaneously however after each change you can reload the animation to include the updates Loading an animation with contours and or deformations for large FE models may take a Please wait con
410. result selected on the Contours tab but always averaged on the nodes See also Contours tab below NOTE Element to Node averaging is not yet supported and even if Load line contours is toggled no contour colors will be shown on the mesh lines when the chosen Result class is Element Fedem Release 5 0 User s Guide 7 23 7 Postprocessing Results 7 3 Animations 7 24 o Load deformations If enabled deformation results from the stress or mode shape recovery depending on the animation type selected are loaded if such results are present See Section 6 6 Stress recovery analysis and Section 6 7 Mode shape recovery analysis Q Load Animation button If you make changes to the animation properties you can reload the animation at any time by clicking this button Time tab Options to control what part of the time history to load See Time tab below Contours tab Options to control what result values to load and display as color contours See Contours tab below Animation types The following three animation types are available Time History Time history animations are used to animate time history results This can be the rigid body component of link motion calculated in the dynamics solver or recovered stress strain and deformational part of the link motion Eigen Mode Eigenmode animations are used to visualize the shape of a system eigenmode at a specific point in time To provide this
411. ride the scale function selected through the Spring property panel if any NOTE The base ID of a mechanism object is normally not visible in the Fedem UI To see the base ID you have to launch Fedem in debug mode using command line option debug Then the base ID appears in curly braces in the Object Browser Fedem Release 5 0 User s Guide F Beta feature documentation F 4 Frictions es TIP You can access the description field of a joint spring by double clicking the desired spring entry in the Topology view of the actual joint F4 Frictions An alternative friction formulation is available by specifying the following command in the description field of a friction object Kstick lt k gt where lt k gt is the stiffness that is used to enforce that the friction DOF has no movement when it is in a stick condition This friction formulation is based on the use of a spring with a varying yield criterion see Section 4 7 6 Advanced spring characteristics That is the Max Yield Force is taken as the maximum occurring friction force before the friction DOF is slipping see the Fedem R5 0 Theory Guide Section 6 5 4 Total friction F5 Tires The following commands can be entered in the description field of a Tire to alter the characteristics of the tire models MF Tyre and SWIFT only SteadyState use the steady state formulation instead of the dynamic one MirrorTChar mirror the tire characteristics about t
412. rlands 1998 2 Maurice J P Short Wavelength and Dynamic Tyre Behavior under Lateral and Combined Slip Conditions PhD Thesis Delft University of Technology The Netherlands 1999 B 2 Notation The equations in the model are expressed in dimensionless quantities as much as possible This is achieved by the introduction of various reference values that are described in this section The reference speed Vg is the speed at which the contact slip characteristics are measured This reference speed is used with the nominal tire radius Rg for calculation of the reference wheel rotational velocity 9 in accordance with Equation B 1 B _ Fo Q R B 1 The reference stiffness for translation Cio is derived from the nominal tire load F 9 and nominal tire radius Ro in accordance with Equation B 2 and the reference stiffness for rotation C is given in Equation B 3 F Cs EA B 2 Cro F gRo B 3 Fedem Release 5 0 User s Guide B 3 B Using the SWIFT Tyre Model B 2 Notation B 4 Dimensionless damping is defined in Equation B 4 in which m represents the inertia c represents the stiffness and k the damping as is common for simple mass spring systems Additionally reference values for damping of translations k and rotations k are defined in Equation B 5 and B 6 respectively k K B 4 24mc moF 0 k Hu B 5 3 K o J MoF Ro B 6 The reference moment of inertia lo is calculated using E
413. rmation about the ft1 format 2 3 2 FTC format The Fedem Technology Cad tc format is used to store CAD geometry in text format Fedem Release 5 0 User s Guide 2 3 2 Learning the Basics 2 4 Starting Fedem 2 3 3 Other supported formats Fedem can import FE models see Section 4 1 1 Creating links by file import in the MSC Nastran Bulk Data File bd or nas format see Section C 2 Nastran Bulk Data File format the ABAQUS inp format and the Ansys anf and cdb format Earlier versions of Fedem used the Fedem Link Model 1m format for FE models These files can also be imported and saved to the t 1 format Fedem can also import CAD geometry from VRML files wr vrm1 vrl wrz for visualization of Generic Parts see Section 4 1 Links 24 Starting Fedem Fedem can be started from a compatible CAD system from the start menu or from the command prompt On windows systems gt To start Fedem with a new empty model press the Fedem icon on the windows desktop or in the Programs menu 9 To start Fedem and open an existing model double click the icon representing the desired model file in windows explorer gt Open a command prompt navigate to the installation directory and enter edem optionally followed by some command line options See Section E 1 Fedem UI Options fedem gt To start Fedem from the CAD system refer to Section 2 12 Using the CAD integration On uni
414. rocess is started a new directory called response_ summary_rcy_ lt ID gt _ lt linkname gt _ is created and the files needed by fedem_fpp are written to this directory These files include an t1 file with Strain Coat elements and the option files co fop and fao The Strain Coat elements are of a non structural type and do not affect the link reduction results NOTE The t 1 file written to this directory is not necessarily identical to the corresponding file in the link repository depending on whether the model has been saved since the strain coat elements were created Fedem Release 5 0 User s Guide 8 11 8 Managing Results 8 3 RDB directory structure 8 12 Fedem Release 5 0 User s Guide A Using the MF Tyre Model SSS AppendixA Using the MF Tyre Model Delf yre This chapter contains proprietary information of TNO The contents of this chapter may not be disclosed to other parties copied nor duplicated for commercial use without the prior written permission of TNO The Magic Formula MF Tyre tire model is developed by TNO Automotive MF Tyre is the premier handling tire model available in Fedem This chapter includes the following sections About MF Tyre MF Tyre Version 5 2 Tire Road Interaction Axis Systems and Definitions The Magic Formula Tire Model MF Tyre Steady State Magic Formula Some Practical Aspects Standard Tire Interface STI MF Datasets and MF Tool D
415. roup of options are available on the joints Origin tab The two toggles shown below control whether the slave and or the master triad will move along with the joint symbol if the joint itself is moved See also Section 3 5 4 Origin property and Section 3 5 2 Align CS and rotations Relative positioning of Triads V Master triad follows joint Slave triad follows joint Fedem Release 5 0 User s Guide 4 29 4 Mechanism Elements 4 4 Joints The sensitivity of the Position and Orientation fields in the Origin tab of the joint and its triads will reflect the movability of the selected object and may change when changing these options E g triads attached to FE nodes can not be moved an thus if the triad is set to follow the joint the joint can not be moved either NOTE These settings do not apply when you are using the Smart move command to move the joint see Section 3 5 1 Smart Move When applicable the Smart move command will always move the master triad along with the joint The Slave triad follows joint toggle affects the Position of the slave triad only The Orientation of the slave triad in a point to point joint will always follow that of the joint itself The joint rotation variables are defined as the rotation between the joint coordinate system and the slave triad coordinate system and thus the triad rotation is controlled by the rotational joint variables alone When creating a point to point joint the defaul
416. rted to The default is to save OK the animation to model file root with same name as in animation s description Default file format is mpeg 1 You can choose between the following operations All frames The animation will be exported as is The speed of the exported animation will depend solely on the simulation s time step size Real time The animation will be exported so that one second movie time corresponds to one second of simulation time Note that the animation s frame rate is 30 Hz so this will be an approximation omit every nth frame Every nth frame will be omitted when exported Q Export only every nth frame Most useful when you have solved using small time steps and want finer control over what you export Fedem Release 5 0 User s Guide 7 39 7 Postprocessing Results es 7 40 7 4 Viewing animations Hints and tricks When exporting to mpeg the mpeg 1 format produces smaller files than the mpeg 2 format and the quality is approximately the same For best result use black background It seems that the MS Media Player has problems playing the exported mpegs on some machines If you discover this you can try to play the animations with the Elecard mpeg player http www elecard com If you are working on Windows we recommend exporting to avi Avi export is faster and also produces better quality When you export to avi a dialog will pop up where you can set up which codec to use
417. rtionally scaled to zero output A 8 Standard Tire Interface STI As aresult of the First International Colloquium on Tire Models for Vehicle Dynamics Analysis on October 21 22 1991 the international Tire Workshop working group was established TYDEX The working group concentrated on tire measurements and tire models used for vehicle simulation purposes For most vehicle dynamics studies people usually develop their own tire models Since all car manufacturers and their tire suppliers have the same goal that is development of tires to improve dynamic safety of the vehicle standardization in tire behavior description should be aimed for In TYDEX two expert groups were defined with following goals The first expert group Tire Measurements Tire Modelling has as its main goal to specify an interface between tire measurements and tire models The work shall include a description of the test Fedem Release 5 0 User s Guide A 35 A Using the MF Tyre Model A 9 MF Datasets and MF Tool A 36 A 9 conditions The interface could be described as a definition of a method or format to describe tire measurement data in such a way that it contains all necessary items to fit tire models to the underlying data The format shall also allow for a description of the test conditions The second expert group Tire Modelling Vehicle Modelling has as its main goal to specify an interface between tire models and simulation tool
418. s See Chapter 5 Control System Modeling for detailed descriptions of control objects gt Control Tools contains commands for manipulating the control system See Chapter 5 Control System Modeling for information about modeling control systems Manipulating toolbars Only some of the commands accessible from the T toolbars are displayed You will see that there are Bhs 8 s t y arrows W beside some of the icons To access amp Revolute Joint other commands click and hold down the W es Ball Joint button A pull down list of additional related ey oe commands is displayed example at right Selecting Me Eelim a command from the list initiates the command and amp Free Joint replaces the button s function with that of the new command You can select another option at any time by clicking holding down the W button and selecting a different command Fedem provides several ways to manage toolbars Fedem Release 5 0 User s Guide 2 Learning the Basics 2 5 Touring the interface Right click a toolbar handle and select an option to relocate show or hide the toolbar Right click an empty space in the toolbar area and select an option from the list to show or hide a toolbar Double click a toolbar handle to show or hide the toolbar VV Y Y Drag a toolbar handle to the left right top or bottom of Fedem s main window to relocate the toolbar 2 5 3 Model Manager The Model Manager panel contains
419. s a 4 amp yJoints Links 1 Front 2 Boom id Be 2 Zoom To i le 5 Bu Create gt rLoads Bl Referer A Strain n Show Element Faces H A Triads Y Copy Link Change Link Hide Element Faces You may also launch FE Fatigue on a selection of element groups However that has the same effect as launching FE Fatigue on the link which the selected group s Generate Strain Coat Reduce belong to gto Export Object Stresses Sort by ID Strain Rosettes Sort by Name Strain Coat Summary Delete Del NOTE nCode software needs to be installed on the computer to be able to run this command NOTE The environment variable npath needs to be set to point to the nCode installation for the application to start In addition the path to the nSoft directory in the nCode installation must be in your PATH On Windows if nCode is already installed when you install Fedem the installer takes care of this 6 9 7 Licensing needs To be able to run the strain coat analysis with FPP file creation you will need both a license from Fedem Technology and nCode 6 10 Duty cycle analysis When you run a Duty Cycle analysis you create a weighted sum of the damage from several load events The results can be viewed with a Time Summary Animation NOTE Currently Duty Cycle analysis can only be performed when the damage is computed using nCode It cannot be combined with the internal fatigue solver 6
420. s and then save the model file and the obtained results before the command exits Thus this has the same effect as but is normally faster the following manual operations Start the Fedem Ul interactively in the normal manner Open the desired model file Launch the desired solver process from the Solvers toolbar Exit Fedem with saving of model file In the same way as when running from the Solver toolbar or from the Solve menu it is checked that all links are reduced and up to date and that dynamics results exist before a recovery process is started And if needed the necessary pre requisite solver tasks are executed first Thus to simply run all recovery types on all links for a given model file you can just use the option solve alland all required solver tasks will be executed sequentially without user interaction 6 14 2 Preparing for batch solving on remote computers Sometimes it is desirable to execute solver processes directly on another computer than the Fedem Ul is run on and which have a separate file system It is then necessary to create the needed RDB directory structure locally populated with all the required solver input files and then manually transfer it to the remote computer for batch execution see Section 8 3 RDB directory structure for details on the RDB structure When finished the whole directory structure can then be copied back onto the local computer for further post processing in th
421. s Intentionally use of this interface will ensure that a wide range of simulation software can be linked to a wide range of tire software available Both expert groups consist of participants of vehicle industry passenger cars and trucks tire manufacturers other suppliers and research laboratories The large number of participants indicates that there is a need for this kind of standardization work DVR is strongly involved in TYDEX At the Second International Colloquium on Tire Models for Vehicle Dynamics Analysis on February 19 and 20 1997 the final documents on both interfaces have been presented 9 The TYDEX Format 1 describes a standard format for the exchange of tire testing and modelling data the second document describes the standard interface between tire model and vehicle model called the Standard Tire Interface STI 2 At the moment a concept for the description of the Tire Modeling Vehicle Modeling interface have been developed and will be tested within the different companies This interface is named the Standard Tire Interface STI 2 The Standard Tire Interface prescribes a subroutine call with a number of subroutine arguments to pass all relevant information from tire models to multi body programs and vice versa The subroutine represents a shell around tire software and is fixed to the axle hub which is modelled by the multi body programs MF Datasets and MF Tool The final objective of the user is t
422. s depending what you select from the Life unit drop down start Stop Entire You can specify what part of the curve to use for fatigue calculations by setting the Time Interval options If Entire is toggled on data for the entire domain of the curve is used If Entire is toggled off the time interval is specified by the Start and Stop fields NOTE If the y axis of the curve is scaled the scaling factor will be applied to the damage calculations too See Section 7 2 7 Scale and Shift View control In graph views you can manipulate the display using the Zoom and Pan toolbar shown below For use of these commands see Section 2 7 3 Zoom and Pan amp eme oss s You can also use the Dynamic Pan F1 and Dynamic Zoom lt F2 commands in the same way as they are used in the Modeler window see Section 2 7 1 3D Navigation s Guide 7 17 7 Postprocessing Results 7 2 Graphs TIP The following tips are useful for viewing graphs gt Ifthe quantity of points in your graph is very large dynamic panning and zooming can take a long time use the commands on the Zoom and Pan toolbar instead to speed up graphic performance gt You can use the Zoom Window command to zoom in on a small area enabling you to see the curves in that area with greater detail This command is turned on whenever the Z key is pressed while viewing a graph area The contents inside the zoom rectangle will be scaled to fit insid
423. s for details Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints Summary table The summary table displays an overview of the settings for each joint variable The columns relate to the fields in the Joint variable properties described above Summary Origin Rx Ry Rz Advanced Constraint Load Model length Init disp Length change Spring Spr scale Damper D Dmp scale 0 0 0 0 1 Rx Free Ry Free 0 0 0 0 Rz Free 0 0 0 0 gt Constraint Shows the Constraint type selected for the joint variable Load Shows the load applied to the joint variable gt Model length Shows the modeled length angle of the joint variable Init disp Initial deflection This column shows the initial deflection set up for the variable gt Length change Displays the function if any that controls the change 4 of length angle of the joint variable If the constraint type is set to Prescribed this change is directly applied to the joint DOF If the Constraint type is set to Spring Damper however this function controls the Stress free length angle change of the spring Spring Spring characteristic Either a number describing a constant stiffness of the spring or a description of the spring characteristics used as a non linear stiffness or force deflection relationship 9 Spr scale The description of the optional function that can be used to scale the force developed
424. s moved slowly the control of the rotation becomes finer and makes it possible to accurately control the view along long constructions Select Rotation Center F4 Select The Select Rotation Center e command enables you to select a new center for zooming and rotation When you use the F4 function to select a point the selected target point shifts to the center of the window and becomes the new dynamic center used by the Zoom F2 and Rotate F3 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 7 Visualizing the model H commands This target point remains the dynamic center until the model is moved by some other view command To select a new rotation point press and hold down the F4 key move the cursor to the target point and click the left mouse button TIP To closely examine a part of your model set the dynamic center F4 at the point of interest and use Zoom F2 to magnify the view You can then easily examine the point from many directions using Rotate F3 Keyboard keys To rotate the model by increments of 15 degrees use the arrow keys Rotation and panning may also be done by pressing Shift rotate 90 degrees Alt rotate around screen normal or Ctrl panning in combination with arrow keys To zoom in and out press z or Shift z Predefined view tool buttons Isometric To display an isometric view of your mechanism click the Isometric button Top To display the top view
425. s or if Fedem stops responding check the console window if activated and the output list discussed later for important information Take note of any errors or warnings before contacting Fedem technical support support fedem com Once the initial tasks are completed the Fedem main window is displayed The following sections describe Fedem s user interface Touring the interface Starting with an empty model file the Fedem main window appears as File Edit View Tools Mechanism Control Solve Result Windows Help Deh S 44 gt oZWJBREBEmESTE GGeee e sss F 2 5 1 Fedem s main window shown below Fedem R5 0 untitled 5 fmm VE Ya E D t Ai Hee SA ess Res eas E M Referenca planes Done Cancel Objects Resuts E Bl Reference planes 2 6 AARAL v paos mm z Bo z 00 a0 00 Size Height 7 0 Width 7 0 m Global z Dy f EueZx asx Y Z Rot Deg 00 Orientation Coordinate type Coordinate type Fedem Release 5 0 User s Guide 2 Learning the Basics 2 5 Touring the interface sy Menus and toolbars contain buttons used to initiate commands Model Manager panel contains the Objects and Results tabs which allow you to create manage and delete the objects in your model and define animations and graphs of your results Q Guide panel This guide will pop up above the Model Manager panel when you invoke
426. s 4 4 Joints Ball joint The ball joint has three DOFs that allow es i rotation of one link with respect to another about three axes The joint variables are defined by the angles between the master triad and the slave triad in the x y and z directions The symbol for a ball joint is displayed in the Modeler window as shown to the right The cross in the middle of the sphere represents the slave triad The lines extending out of the sphere represent the master triad Q The circles represent the joint itself You can add friction to a Friction ball joint by selecting one Rotational friction 7 from the list of frictions in Giver LIEST your model in the Friction pull down list Then you also need to select which one of the three joint DOFs that shall receive the friction moment The effective normal load in the friction is then computed from the other two joint DOFs that are orthogonal to the selected DOF See also Section 4 6 Frictions and the Fedem R5 0 Theory Guide Section 6 5 Joint Friction Rigid joint The rigid joint constrains all displacement T m between two links and is therefore used as a stiff connection It has no joint variables The symbol for a rigid joint is displayed in the Modeler window as shown to the right 1 A The cross in the middle of the cube X o represents the slave triad The lines extending out of the cube m a represent the maste
427. s The rigid surface connector is a rigid connection between the triad and all the FE nodes it connects That means that all the FE nodes connected with the surface connector becomes one rigid block The rigid surface connector is visualized with dashed lines Fedem Release 5 0 User s Guide 3 17 3 Mechanism Modeling 3 6 Attaching and detaching elements 3 6 3 A amp 3 18 Surface connector commands There are two ways of creating a Surface connector By selecting nodes or By cylinder surface The commands can either create a new connected triad at a user defined position or connect an existing triad to the FE mesh in somewhat the same manner as the Attach command By selecting nodes These commands are used to select arbitrary nodes or areas of nodes to use for the surface connector To create a Surface connector by selecting nodes complete the following steps 1 Select either the rigid or flexible version of the command Kr St S23 F YIL bo M X Rigid surface gt AEE 2 First you have the option to either select an existing triad which might be embedded in a mechanism element or to select a position where you want a new triad to be created If you pick a triad that triad will become selected and will be attached through the surface connector If you pick something else the snap point will be used as the position for a new triad If you get it wrong try again until you have selected what
428. s of the Magic Formula The general form sine version of the formula reads Y x Dsin Carctan Bx E Bx arctan Bx A 12 where Y x is either F or Fy The self aligning moment M is calculated by using the lateral force F and the pneumatic trail t which is based on a cosine type of Magic Formula Y x Dcos Carctan Bx E Bx arctan Bx j A 13 Figure A 8 Curves Produced by the Sine and Cosine Versions of the Magic Formula Ya C Bxm tan 7 2C C gt 1 D Bxgyarctan Bx A 2 C z arcsin ER E Bxo tan n 2C Werte sin Bxg arctan Bxo C51 Fedem Release 5 0 User s Guide A 13 A Using the MF Tyre Model A 5 The Magic Formula Tire Model MF Tyre When the formula is used to calculate the forces generated by the tire the following variables should serve as input for the Magic Formula Input Variables Longitudinal slip Slip angle Camber angle Normal wheel load R n nm zZ rad rad N In case the complete model including transient properties is used the transient tire quantities are employed instead of the wheel slip quantities Kanda Output Variables in contact point C Longitudinal force Fy N Lateral force Fy N Overturning couple My Nm Rolling resistance torque My Nm Aligning torque M Nm Basic Tire Parameters Nominal rated load Fzo N Unloaded tire radius Ro m Tire belt mass Mpe kg Furthermor
429. s on virtual strain gages on the links based on the Dynamic Solver results The output is time history data of stresses and strains similar to output from real strain gages 1 6 Fedem Release 5 0 User s Guide 1 Introduction to Fedem 1 7 Fedem solver modules 1 7 6 Strain Coat Analysis The Fedem Strain Coat Analysis recovers the stresses and strains on the strain coat elements in the model and calculates a summary of the recovered results over its entire time history The output from this analysis is maximums of certain stress strain quantities over time 1 7 7 Curve Export Utility The Fedem Curve Export Utility module allows you to automatically export a set of curves to a single ASCII RPC file The result data on which the curves are defined can be distributed on several results database files B This program module can only be run separately as a batch process Fedem Release 5 0 User s Guide 1 7 1 Introduction to Fedem 1 7 Fedem solver modules 1 8 Fedem Release 5 0 User s Guide 2 Learning the Basics p n W Chapter2 Learning the Basics This chapter outlines system requirements explains where models and results are saved and introduces the Fedem user interface and common commands Sections in this chapter address the following topics System requirements Software requirements Storing models and results B Starting Fedem Touring the interface Executing commands Visualizing the model Openin
430. s to the same nodes in the same order and attaching the two slave triads to the same link on different nodes The joint variable for prismatic joints is the distance from the first master to the slave triad in the direction of the local z axis The symbol for a prismatic joint is displayed in the Modeler window as shown to the right First master triad The slider path represented by a line from the first to the last master Q Slave triad Last master triad Adding masters A prismatic joint is created by selecting the position of the first and last master triad The slider path is then defined as the straight line between the two triads However the slider path may be redefined by adding more master triads along that line This improves load distribution during the simulation as the forces from the slave triad are distributed to the two masters closest to the current position of the slave To add master triads to a joint click the Add Pinte E fo Master button located below the Topology Ft Sieve Trid panel shown at right and select additional FE nodes along the slider path i Master Triad 2 5 Master Triad 3 Joint springs i LTz Joint spring 1 Joint dampers i Tz Joint damper 1 NOTE You can add master to a prismatic joint only after it has been attached to a link see Section 3 6 1 Attaching using Attach It is not possible to add masters to a joint that is attached to ground Add Mast
431. s value for each link by editing the model file 4 Outline No 1D elements Same as Outline except that all Surface Connectors and 1 D elements such as RGD WAVGM BEAM2 are also removed from the display 5 Simplified This option generates a simple line visualization of the link based on the Triads attached to it One line is drawn from each Triad to their geometrical center This option makes most sense if the polygons are turned off This visualization is the same that is used if the link is not loaded see Section 2 9 1 FE Data Settings 6 Off Setting the line detail to Off turns all mesh lines off TIP To edit the appearance or level of detail on several links at the same time select multiple links in the Model Manager Objects list after clicking on the Item Appearance icon Fedem Release 5 0 User s Guide 2 27 2 Learning the Basics 2 7 Visualizing the model 2 7 6 2 7 7 2 28 Element face visibility The visibility of element faces can be controlled using the Hide Element Faces and Show Element Faces commands in the right click menu in the Objects View These commands can be applied to the entire link or to a selection of the element groups listed in the Objects view The icon in front of each group entry in the list indicates the current visual state of the elements in that group Either all visible 4 some visible 4 or all hidden amp These commands will only be active when the polygon detail level is s
432. sage D 2 File usage for each program module D File usage for each program module The table below is an overview of Fedem file usage Fedem application Uses these file types Creates these file types User Interface FE link files ft1 nas bdf 1m CAD geometry files wrl ftc Time history data files asc txt dac rsp drv tim optional Tire description files tpf tir optional Unit conversion file cd optional Fedem results files fxs S N curve definition file sn Model file mm FE link files t 1 CAD geometry files tc Solver input files s1 Solver control files co fop fao Fedem Reducer link reduction FE link file t1 Solver control files co fop fao Matrix files stiffness mass gravitation loads component modes recovery mx Data structure file sm Result files frs ASCII results res Fedem Solver dynamics solver Solver input file 81 Solver control files co fop fao Matrix files stiffness mass gravi tation loads mx Time history data files asc txt dac rsp drv tim optional Tire description files tpf tir optional Road description files rdf optional CAD geometry files t c optional Solver result files 175 optional in case of restart Fedem results files time history response frequency res
433. se Ea estne OE o e Oe Pei UR RUN ER RR 4 37 4 5 2 Rack and Pinion c ccc cece cece c teense eececeeneeeresenneneees 4 38 46 RICHONS 86 ecatonSsorbcessdsibadea aera piacevastensbet coke TE oA 4 38 47 Springs and Dampers o oor v IN Dd see My ROA 4 39 4 7 1 Spring Properties e eek en rone ee eret Re HE AERE Rare 4 40 4 7 2 Damper properties sssslseeeeeeeee he Hh 4 41 4 7 3 Axial spring symbol vr err Ier e or RE HR RR ed 4 42 4 7 4 Axial damper symbol 0 0c cece cece ene e cece ence heme en 4 42 4 7 5 Spring and damper characteristics 0 cece cece e eee e eee e nes 4 42 4 76 Advanced spring characteristics 0 cece cece cece ence eee erreren 4 44 48 loads res rra FERA E METER levees MN S UE VE 4 46 4 8 1 Load symbols oode cx hr eer aE ir gere wed tos e Un et 4 46 4 8 2 Load properties sirere rri cece cece cece ence e cence ene e en EEE aE 4 47 4 8 3 Target polnt eR sings EC ERE DES TUE ET RS 4 47 4 8 4 Die pm CEP 4 48 Fedem Release 5 0 User s Guide vii 4 9 4 10 4 11 4 12 Chapter 5 viii 5 1 5 2 5 3 Tir sand Roads nia dd RO E x Ry aes tcc eR 4 48 4 9 1 TRG Sekt T 4 48 4 9 2 Roadie renei ine E a E Ea Oona ead T Meek 4 49 4 9 3 Road elevation isan Deuce pereo eq EAE E E EA AAS 4 50 FUDCUONS c Sees E E E E ERA treet que EE 4 50 4 10 1 Creating a function eeaeee a EE meme 4 51 4 10 2 Function properties ccc ccc cence eee een eee nee men 4 51 4 10
434. siderable amount of time However it is iil SP possible to cancel the animation loading process at any time by using the Cancel button of the progress dialog that appears while the animation is loading shown to the right Closing animations E You can end an animation session at any time by clicking Close on the Play Panel or selecting End Animation Session from the Result menu 7 3 2 Animation properties To display the properties of an animation in the Property Editor panel select the animation in the Model Manager Results list The properties for the animation are displayed in the Property Editor as shown below Time Q Q Description Stress 19 T us E Time History Time Window Animation Frames Eigen Mode Complete simulation C For every time step Time Summary Time interval Only for requested results Load face contours Start o IV Load line contours 8 Stop po I Load deformations Load Animation 5 Type The animation type determines the main type of results you want to animate See Animation types below 2 Load face contours If enabled the values specified on the Contours tab are loaded and shown as color contours on the element faces of the mechanism assembly See also Contours tab below Load line contours This option controls whether or not contours are loaded and displayed on the FE mesh lines The values displayed will be the
435. simultaneous visualization and simulation features may use a large amount of system resources Fedem Release 5 0 User s Guide 6 47 6 Mechanism Analysis 6 12 Deleting results 6 11 2 Stop processing Solution processes can be stopped at any time by pressing the Stop All Smr Solvers button on the Solvers toolbar or Solve menu NOTE All results created before the stop button is pressed are stored and can be evaluated in the normal manner 6 12 Deleting results i To delete result files from the dynamics simulation and recovery operations stress recovery modes recovery strain rosette recovery and strain coat recovery click the Delete Results button on the Solvers toolbar or Result menu NOTE Result files are not deleted until you save or close the model and files from the link reduction are never deleted CAUTION If you use the Save As command to save a model to a different location result files from previous solutions are not copied to the new location Only result files and reduced links from the current analysis are copied Applicable only if the Discard results and Discard reduced links toggles are not set 6 12 1 Deleting specific results Results from specific recovery processes can be deleted This is useful for reclaiming disk space or changing the result window available to the post processing The stress recovery results can be deleted by clicking the Delete Stress Recovery results button on
436. sing the Mouse button see Section 4 8 3 Target point below Direction The From and To options allow you to edit the orientation of the load vector see Section 4 8 4 Direction below o Mouse button You can select a new point for the Load Target Point or From or To Directions using the Mouse buttons then select a new point in the Modeler window Q view button You can click and hold down any of the View buttons in the Property Editor to highlight the corresponding point in the Modeler window 9o 3 4 8 3 Target point To specify a new target point click the Mouse button and use the cursor to select a link in the Modeler If the target point does not coincide with co an FE node the target point will snap to the closest node Press Done to confirm the selection A triad is created at that position Fedem Release 5 0 User s Guide 4 47 4 Mechanism Elements 4 9 Tires and Roads EE 4 8 4 Direction The direction of the input load vector can Force wactor be specified by two points moving together with the selected links or by From point two fixed points given in global X coordinates The direction is given by the vector pointing from the From point to 5 the To point shown at right Target Point X To point 4 9 Tires and Roads Tires and roads are used to simulate the behavior of rubber tires found on many vehicles such as cars trucks and planes Fedem currently interfaces tire models
437. sing the SWIFT Tyre Model B 3 Force Evaluation radius is a function of speed as the tire grows with speed as given in Equation B 18 2 Arg qy4Q B 18 The free tire radius is calculated using Equation B 19 and is displayed as function of the wheel speed in Figure B 4 Ro Freq Arg Rg B 19 The normalized vertical tire deflection is defined by Equation B 20 P tg R R B 20 The overall vertical tire force is a function of the tire deflection wheel rotation velocity and slip forces as given in Equation B 21 zio 2 55 F ay apea ag Fs peaks Gp Pr B 21 Figure B 4 Free Tire Radius as Function of Wheel Speed 1 005 at standstill Normalized tyre radius 1 0 995 0 99 0 3 0 6 0 9 0 1 20 150 Wheel speed rad s Fedem Release 5 0 User s Guide B 11 B Using the SWIFT Tyre Model B 3 Force Evaluation Figure B 5 Vertical Tire Force and Stiffness Tyre Force Vertical stiffness Normalized tyre force 0 5 0 0 5 1 15 2 Normalized tyre deflection As shown in Figure B 5 the vertical tire force as function of the deflection is a parabola The vertical stiffness value in the tire property file C is the stiffness at the nominal tire load The relation between C qr 1 and grz is given by equation B 22 F 0 2 C R d Fz1 4d p29 B 22 The vertical force characteristic for different wh
438. solute tolerance in control iterations 0 002 ctrlTolRel Relative tolerance in control iterations 0 002 ctrlfile Name of control system database file ctrl frs curveFile Name of curve definition file response bak fmm curvePlotFile Name of curve export output file curvePlotPrec Output precision for exported curve data 0 files 0 half precision int 2 1 single precision real 4 2 double precision real 8 curvePlotType Format of curve export output file 0 0 ASCII separate file for each curve 1 DAC Windows separate file for each curve 2 DAC UNIX separate file for each curve 3 RPC Windows all curves in one file 4 RPC UNIX all curves in one file 5 ASCII all curves in one file cutbackFactor Time step reduction factor in cut back 1 cutbackSing Try cut back when detecting singularities false cutbackSteps Number of cut back steps 0 cwd Change working directory damped Solve the damped eigenproblem using false LAPACK datacheck Do data check only exiting after data false input debug Debug print switch 0 delayBuffer Initial buffer size for delay elements 1000 densesolver Use LAPACK dense matrix equation solver false double1 Save primary variables in double precision true double2 Save secondary variables in double preci false sion ef fModalMass Compute the effective mass for each false mode eigenshift Shift value for vibration eigenva
439. specify a non existing option the option is ignored A warning for each unrecognized option is the printed to the console window or in the Output List if executed through the user interface Sections in this appendix address the following topics Fedem UI Options fedem Link reducer options fedem_reducer Dynamics solver options fedem_solver Stress recovery options fedem_stress Mode shape recovery options fedem modes Strain rosette recovery options fedem_gage Strain coat recovery options fedem_fpp VVVVVVYVY Curve export options fedem_graphexp Fedem Release 5 0 User s Guide E 1 E Command line options ee E 2 E 1 E 1 Fedem UI Options fedem Fedem UI Options fedem Command line option Description Default value checkRDB Time ms between each RDB 500 interval check update during solve connect ToSw Connect to or create a SolidWorks session false console Enable console window false debug Run in debug mode false f Model file to open untitled fmm help Display this help and exit false licenseinfo Print out license information at startup false logFile Write all Output List contents to log file true Log file name lt modelFilePrefix gt log noAddOn Do not use licenses for add on modules false noFEData Load model file without FE Models and false FE Results info Use together with f plotElements
440. stance the Control Editor window x Toso Y 0 50 Close Inserting blocks To insert control system blocks complete the following steps 1 Clickthe button that represents the block you want to insert TIP You may have to hold down the arrow found next to a block of a similar type to access the drop down menu with other block selections 2 Move the cursor into the Control Editor You will see the block following the mouse Place the block where you want it and click the left mouse button to drop it NOTE When a block is inserted in the Control Editor window it is automatically added to the Model Manager Objects list Moving blocks You can adjust the block position by positioning the cursor over the block pressing the left mouse button and dragging the block to the new position When the block is correctly positioned release the mouse button Several blocks can also be moved together To do that press and hold the Ctrl key then select the blocks you want to move and finally drag them to the new position Fedem Release 5 0 User s Guide 5 Control System Modeling 5 4 Building control modules 5 4 4 5 4 5 IE Fedem Release 5 0 User s Guide Editing block properties Once a block is inserted in the Control Editor you can edit its properties by selecting the block and editing the properties in the Property Editor window For example the equation and properties of a PID control block are shown
441. stem Triads optional nodal points that are defined as external during the construction of an FE model in an external modeler are automatically x connected to a triad when the p link is imported into Fedem If oO T external nodes are not defined in the FE model file no triads will appear when the model is imported see Section 4 3 Triads for more information about triads Local coordinate systems Local FE coordinate systems present in the imported FE mesh is read and displayed for reference 4 2 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links Generic Parts A Generic Part is a simplified flexible body It is purely defined by its connection points mass properties and stiffness at the connection points The stiffness can either be defined manually or automatically set to some very high value mimicking a rigid body See the Fedem R5 0 Theory Guide Appendix A 16 Generic Part element for details on how a Generic Part is represented in the Dynamics Solver Generic Parts can be used when you have no FE model for the link when trying to optimize hardpoint positions or when the flexibility of the part is considered to be insignificant They can also have a VRML geometry attached to give better visualization of the link Shown below is a link defined as a Generic Part with two triads anda Revolute Joint connected to it o Link coordinate system At the time of creation th
442. sults from the complete simulation time are produced and displayed It is however also possible to show an animation of how the results are accumulated by running the Strain Coat Recovery Summary several times with different stop times Time tab If you selected Time History as the animation type in the Property Editor you can choose to show the entire simulation default or a specific time interval To change the interval you must specify the properties on the Time tab shown below in the Property Editor before loading the animation The Time tab is not available for Eigen Mode and Time Summary animations Time Contours Time Window Animation Frames Complete simulation C For every time step C Time interval Only for requested results Start Stop Jim Time Window You can choose to display the entire duration of the 7 simulation or a specific time interval If you select Time Interval enter values for the interval s Start and Stop time Animation Frames These options are useful if you specified different time steps for the dynamics simulation and the stress recovery calculation see Section 6 6 1 Stress recovery options Enabling For every time step loads deformation results and color contour values for all the time steps calculated within the time window specified NOTE Enabling For every time step shows continuous motion however the stress color contours may flash on and off if the
443. t SWIFT Vertical only 0 0 20 Longitudinal only 1 11 21 Lateral only 2 12 22 Long and lat uncombined 3 13 23 Combined slip 4 14 24 In case of transient behavior the belt stiffness is taken into account as well as the contact length for the calculation of the tire relaxation length The longitudinal relaxation length is calculated from the SWIFT stiffness using Equation B 38 which incorporates a scaling factor 2 7 1 1 o latki t New B 38 c Cro bx Crx Similarly the lateral relaxation length is calculated from the SWIFT stiffness using Equation B 39 note that Ky is a negative quantity including a scaling factor 6 7 a K 1 lyfe X B 39 j Chy Cry Cy T Tire Model Parameters The tire parameters that are defined in the tire property file are related to the model structure in Figure B 16 For each of the parameters a reference to the equations in this manual is given The full context of the parameters can be understood by looking up the appropriate equations in this guide The SWIFT specific parameters are listed below MF Tyre indicates that the parameter or group of parameters is also used for B Using the SWIFT Tyre Model B 4 Tire Model Parameters MF Tyre For more information on those parameters see Appendix A Using the MF Tyre Model Figure B 16 Tire Parameters in Model Structure Overall tyre stiffness Nonlinearities Q_FZ2 Speed effects Q_V2 Side
444. t Mode Synthesis CMS model reduction method that replaces the internal nodal DOFs with a set of static and component modes The static modes corresponds to the external nodal DOFs i e at the Triads attached to the link whereas the component modes are calculated as the eigenmode shapes of the link with all external nodes fully constrained Component modes describe the internal vibrations in the link You should normally include a sufficient number of modes such that the frequencies within the time step size used in the dynamics simulation are covered The frequencies of the computed component modes are found in the output file fedem reducer res which can be viewed using the Result File Browser see Section 8 2 Result File Browser The number of component modes is specified in the Property Editor panel for the selected link see Reduction Options tab in Section 4 1 4 The default is O no component modes i e only static modes are used If the internal vibrations are not important for the overall response you can save computation time by using static modes only More details on component modes and CMS model reduction can be found in the Fedem R5 0 Theory Guide Section 3 2 Component mode synthesis reduction Fedem Release 5 0 User s Guide 6 11 6 Mechanism Analysis 6 3 Model reduction E 6 3 3 Using lumped mass matrix To increase the computational efficiency of the model reduction process a lumped mass matrix approach
445. t and select mport and Import Graphs In the file dialog that pops up select one or more graph files you want to import One graph is created for each of the selected files containing one curve for every channel in the file 7 2 14 Exporting to picture files You may also want to export a graph view to a picture file This is accomplished by first selecting the graph window you want to export and then selecting Export and Export View from the File menu You may choose to output in either BMP JPEG or PNG file format See Section 2 10 2 Exporting for more about Fedem s export capabilities 7 20 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 3 Animations sy 7 2 15 Printing graphs When a graph window is active you can send its contents directly to a printer for printing Select the printer symbol on the tool bar or the Print With Setup command in the File menu When selecting the latter you will be able to select which printer to use paper format and so on 7 3 Animations Fedem animations are used to visualize the motion or the structural results of your model in an intuitive and life like fashion Fedem is able to utilize link motion link deformation and link color contours to visualize your results and help you understand them TE DEW e ozBJmgEnmmE Ge e s V A E t Ag 0 Biz gt 9e 006 gue F EHtety 7e 006 5e 006 e 006 H h Lal 2e 006 4 a Slow Rea
446. t are available to the user License information Module Name Version Available but not checked out FA CTI Control interface add on FA CTR Control add on FA DRB Durability add on FA TII Tire interface add on Fedem Release 5 0 User s Guide 2 Learning the Basics 2 11 License information 2 11 2 2 11 3 2 11 4 2 38 For example when loading a model that has control elements the control interface add on license FA CTI is also checked out This license is held by the application until the model file is closed again The license information list is available at any time from the License information command in the Help pull down menu License denial If the requested add on license is unavailable either in use by another session or not a part of the license contract then modeling manipulation and solving of objects covered by that license is denied e g control block editing is not allowed while the control interface add on is missing Post processing including graph and animation handling is always allowed as long as the modeler core license is available License file server The current license file server used is also shown in the license information listing Managing license files servers By selecting the License Manager from the Help menu you are able to add or remove license files servers You may also paste a new license text directly into the default license field See the Fedem
447. t to use See Section 3 9 1 Model database units e Modeling tolerance The maximum allowed distance between the FE node and its attached Triad See Section 3 9 2 Modeling tolerance o Sea environment If the mechanism model or parts of it is submerged in water or any other liquid you may account for buoyancy if the Water Model Preferences Model description P Model database units Modeling tolerance 3 Absolute modeling tolerance 0 0001 Sea environment Water density 0 Sea water level 0 0 Gravitation x foo x 9v oo amp sn 2 Model link repository zi Initial translational velocity foo foo oo internal Change Switch to external repository OK Apply Cancel density and Sea water level is specified See Section 3 9 3 Buoyancy Q Gravitation The gravitation vector direction and magnitude See Section 3 9 4 Gravitation Q Initial translational velocity The initial translational velocity of all triads in the model See Section 3 9 5 Initial translational velocity Model Link Repository Switch between external and internal model link repositories You may also Change the external model link repository See Setting the model link repository in Section 4 1 5 NOTE Changes to the Model description notes will be saved also when pressing Cancel or closing the Model Preferences window Therefore you may edit these n
448. t value of the rotational joint variables is zero 4 4 4 Point to path joints Point to path joints are more complex than vy ph He RA point to point joints as they require more than one master triad for each slave The motion is defined by Prismatic Joint at least two master triads in a straight or curved path J Cylindric Joint Point to path joints are found on the Mechanism Creation toolbar shown at right 42 Cam Joint NOTE The same master triads can be used in more than one point to path joint Each of the point to path joint types is described in the following Prismatic joint A flexible prismatic joint consists of a slave triad sliding along a straight Si path defined by two or more master triads The local coordinate system of the joint is defined with its z axis directed along the slide path The x and y axes are defined from the coordinate systems of the master triads The joint has three unconstrained DOFs but only a single joint variable the slider variable that allows you to control the translational displacement of the slave along the local z axis Rotation is constrained about the z axis but not in the other two directions the slave can rotate about the local x and y axes independently of the masters 4 30 Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 4 Joints EE TIP You can attach two prismatic joints to make a stiff translating connection by attaching the masters for the two joint
449. ta before the transform is computed You may not scale or shift the transformed curve Start Stop Entire What part of the curve to transform is specified using the Time Domain options If Entire is toggled on then data for the curve s entire domain is used If Entire is toggled off then a start and stop time may be set in the fields labeled Start and Stop Q9 No0 Hz component The arithmetic mean of the original curve data is reflected in the transform s value at O Hz the transformv s first point To facilitate transform analysis you might want to cancel out the 0 Hz component by using this option Use sample rate The sample rate used in the transform is by default equal to that of the curve data However if the curve has a non constant sample rate the transform will fail In such cases the wanted sample rate may be input using this field CAUTION The Fourier transform needs to be recalculated each time points are added to the curve Consequently if curves are plotted while the Dynamics solver is run then transforming these curves will increase the CPU load during solving TIP A good reference on the theory of Fourier transforms is W Rudin Real and Complex analysis McGraw Hill 1974 7 2 7 Scale and Shift Options to scale and shift the curve data are found on the Scale and Shift tab of the Property Editor panel You may apply scaling and a shift on the curve data independently in the x and y directions The
450. tab The settings on this tab concern the mass and inertia properties of a Generic Part and is used to establish the link s mass matrix see the Fedem R5 0 Theory Guide Appendix A 16 Generic Part element Part Origin CoG Mass Stiffness Advanced I Calculate from FE model o Mass and Inertias Inertia Reference o9 Mass p 0 55mm slm RR A w iy foo foo Ix2 yz goo p po O Mass The total mass of the link Inertias The lower triangle of the inertia matrix at the centre of gravity of the link Inertia Reference Select whether to specify the inertia in the directions of the link coordinate system or in the directions specified as Principal Axes of Inertia on the CoG tab o Calculate from FE model The link mass and inertias as well as the centre of gravity in the CoG tab will be calculated from the FE model when available if this toggle is on The nertia Reference will also be set to Link Orientation and editing of the fields are disabled Stiffness tab The stiffness properties of a Generic Part can be controlled on this tab Part Origin CoG Mass Stiffness Advanced Type C Manual Properties stiffness at each triad 1 000 000 0 Rotational stiffness at each triad 1 000 000 0 Type These radio buttons choose whether to set the overall Generic Part stiffness manually or to have Fedem calculate a near rigid stiffness for
451. ter The external control plug in module supports release 12 1 and 13 i e version 6 1 and 6 5 of MATLAB and version 4 and 5 of Simulink respectively If MATLAB is installed the needed library routines will be dynamically loaded run time 5 5 2 Data exchange The data exchange between Fedem and the Simulink model utilizes the MATLAB workspace A MATLAB session is therefore started when a simulation involving an external control system is initiated The inputs and outputs of the Simulink model must be modeled as From Workspace and To Workspace blocks respectively The data flow in Fedem is different from the data flow in case of internal control system see Section 5 2 Input and output Thus mechanism variables are set up using functions and passed to the control system by selecting the proper functions for each of the control system input values The responses are read by sensors and through functions utilized in loads etc The data flow is visualized in the figure below Input Function E created by you Y External Control System Control Simulink Control Input model Output From Workspace To Workspace Sensor available as Function argument As an example suppose a simple Pl controller has been configured in Change in mechanism E P force magnitude change spring length change or Output Function damper coefficient change Created by you Simulink
452. ter address the following topics Control modeling environment Input and output Control blocks BH Building control modules VVVYVY External control systems Fedem Release 5 0 User s Guide 5 1 5 Control System Modeling 5 1 Control modeling environment 3 5 1 1 5 1 2 Control modeling environment Fedem s block diagram presentation of control systems closely resembles that given in most textbooks about basic control theory The graphical representation consists of a series of connected control blocks which you can model to simulate your control requirements Control Editor To create a control system Fedem provides the Control Editor window in which control systems can be created and manipulated Control blocks are selected from the Control menu or the Control Creation toolbar for placement in the Control Editor window They can then be moved and manipulated with drag and drop functionality This editing environment also features grid and snap functionality see Section 5 4 1 Setting Grid and Snap To open the Control Editor click the Show Control Editor button on the Windows menu or toolbar The Control Editor window is shown below with an example control system Control Editor Control toolbars Fedem provides two toolbars for modeling control systems Control Creation toolbar The Control Creation toolbar shown below consists of the Fedem control blocks that are used to build control modules S
453. ters such that the local workstation can allocate its resources fully to the Fedem UI process To enable such remote solving use the Perform Remote solve options remote solve toggle in the Remote solve options I Perform remate solve part of the Additional Solver Options dialog Remote shell command prefix plink kmo arenadafedemno shown to the right Enter the appropriate F x odel path on remote system Remote shell command prefix needed to run the 1 home kmottest oo solver command on the remote computer and optionally the Model path on remote system The latter is necessary when e g your local workstation is a Windows PC and the remote computer is a UNIX machine You will then need to specify the path to the current model file as it looks from the UNIX computer CAUTION When specifying a remote shell command prefix the input files needed by the solver tasks are still created locally within the Fedem UI and not explicitly copied on to the remote computer Thus a remote execution will work only if the local and remote computers use a shared file system Similarly it is assumed that the Fedem UI on the local computer can access the output files created by the solver task directly from where they are written by the remote computer NOTE A server program accepting remote shell commands must be running on the specified remote computer for this feature to work e g sshd or rshd If using ssh or the equivalent windows client
454. the Events table use the Add button to add the events you want to use for your simulation You may optionally provide a Description Number of repeats gives the weight of the event One of the events needs to be selected as Master This event is the one where you have a complete fpp file i e with material data included Fedem Release 5 0 User s Guide 6 45 6 Mechanism Analysis 6 10 Duty cycle analysis ixi Events m Links Event Descip on Repeats Master d Models Frame HardT um fmm Hard Tum 5 M i LeftKnuckle 2 RightKnuckle d Models Frame Jump fmm Jump 2 3 SteeringRod d Models Frame PanicBraking fmm Brake v 4 Frame Add event Delete event Check all Check none Equivalent unit scale 1 0 Equivalent unit Hour OK Apply Cancel Select the links you want to use in the Links table Note that the links you select must be present in all events and they need to have the same ID in all events as well Next set the Equivalent Unit and the Equivalent Unit scale The Equivalent Unit and scale is the period which consists of the events with their repeats E g in the above picture 6 hard turns 2 jumps and 8 breakings is equivalent to 1 hour of operation 6 10 4 Running Duty Cycle When running Duty Cycle four nCode programs are run in succession on each link First fpphcopy is run to copy the fpp file header from the master model to the other fpp f
455. the Model Manager panel Fedem Release 5 0 User s Guide 2 9 2 Learning the Basics 2 5 Touring the interface n Sorting The objects in the Model Manager can be sorted either by ID number or by item name To switch sorting mode right click inside the Model Manager area and select either Sort by ID or Sort by Name in the menu Default sorting in the Model Manager is based on the ID numbers TIP Right clicking in the Model Manager will display a pop up menu with commands that applies to the current selection The contents of this menu depend on the type of the selected object Objects The Objects tab displays a list of all modeling objects in your model Selecting an item from this list highlights it in the Modeler or the Control Modeler and displays its properties in the Property Editor panel Results The Results tab displays a list of the result views you have created The available result views are graphs which contains curves individual sets of plotted data and animations Selecting a graph from this list will cause the window containing the selected graph to pop up if loaded Selecting a curve will highlight it the curve is rendered red and raise the graph view in which it resides as well The properties of the different objects is shown in the Property Editor panel when they are selected See Chapter 7 Postprocessing Results for more information about graphed and animated results 2 5 4 ID and T
456. the elements All element faces are shown as single polygons 2 Reduced Surface and Internals Setting the detail level to Reduced Surface and Internals displays a simplified polygon representation of the surface and internals of a link This is faster than using Surface and Internals but shows a less accurate representation of the links 3 Surface This option turns off the internal faces in a link and will only show the surface element faces of a link All the surface faces are shown as separate polygons 4 Reduced Surface Setting the polygon detail to Reduced Surface provides the most efficient way to visualize the shaded view of a B mechanism link The surface is displayed using a simplified polygon model and the internal faces are turned off 5 Off Setting the polygon detail to Off turns all polygons off Lines can be displayed at six levels of detail Full Surface Outline Outline No 1D elements Simplified and Off The default level is Outline 1 Full With line detail set to Full mesh lines from solid elements inside the links are shown together with the surface mesh of the elements 2 Surface Setting the line detail level to Surface displays only the mesh lines on the surface of the FE model 3 Outline This option leaves only the mesh lines on the surface of the link with neighboring element faces with a relative face angle above a certain threshold The default threshold is 7 4 It is possible to edit thi
457. tiffScale gt 3 k Max diag K lt autoStiffScale gt autoStiffScale Scale factor for auto added springs 100 Bmatfile Name of B matrix file Bmatprecision Storage precision of the B matrix on disk 2 1 Single precision 2 Double precision Bramsize In core size MB of displacement recov 1 ery matrix lt 0 Store full matrix in core bufsize_rigid Buffer size in DP words per rigid ele 0 ment lt 0 Use conservative estimate com puted internally cachesize Cache size KB to be used by the SPR 0 solver or core memory MB reserved for numerical data for the GSF solver Applies to the stiffness matrix only when lumped mass is used 0 Let all numerical data be in core for the GSF solver consolemsg Output error messages to console false cwd Change working directory datacheck Do data check only exiting after data false input debug Debug print switch 0 eigenshift Shift value for eigenvalue analysis target 0 frequency for generalized DOFs eigfile Name of eigenvector file extNodes List of external nodes to use in the reduc tion in addition to the nodes specified in the link file factorMass Factorize mass matrix in the eigensolver false fao Read additional options from this file fco Read calculation options from this file Fedem Release 5 0 User s Guide E 3 E Command line options E 2 Link reducer options fedem reducer
458. tinuously updated as the file is being written by the solver TIP For the model reduction and all of the recovery modules a dedicated progress file called progress info res is created This file is updated more frequently than the conventional res file associated with the process Viewing this file while the solver is running will therefore give you the best update on its progress It is often wise to also keep an eye on the Output List view while a solver process is running as important messages produced by the solver errors warnings and notes are written here while the process is running see also Section 6 14 2 How to read error messages from the solvers All such messages are also written to the res file but in the Output List they are prefixed by the solver name and the process ID in brackets e g Started Warning Indication of a poor centripetal force on the rotating Link 3 Try distributing the triads better or use centripetal moment correction Finished Wall time elapsed 00 04 07 The first message of a solver process is always Started and the last message is Finished followed by the consumed wall time The process ID number is used to distinguish messages from possibly multiple simultaneously running reduction or recovery processes Model reduction The model reduction process requires no user setup apart from the settings found in the Reduction Options tab of the Property Editor panel for each link see Section 4 1 4
459. tion 5 2 Input and output They can also be created manually using the Simple Sensor and Relative Sensor commands Among the quantities that can be measured are triad positions and joint variables and the associated velocity and acceleration triad forces spring damper force length and deflection velocity and so on Triad rotations can also be measured in terms of Euler Z Y X angles in the global coordinate system or relative to another Triad with relative sensors The data obtained from a sensor can be processed by a function and used in the model or a control system see Section 4 10 Functions and Chapter 5 Control System Modeling There are two types of sensors simple sensors and relative sensors Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 11 Sensors 4 11 1 F 4 11 2 amp 4 11 3 Simple sensors Simple sensors are used to tag a single mechanism element such as a joint or triad in order to extract measurements from it When an object is tagged with a sensor it will appear in the Argument drop down menu in Functions and the Input menu in Control Inputs In addition a 3D symbol will be created to show that this particular object is being measured The symbol for a simple sensor is displayed in the Modeler window as shown to the right Relative sensors Relative sensors are used to tag two triads in order to extract relative measurements from them The sensor will be displayed in
460. tion also works when running the solver in batch mode even when the fedem solver fsi file is loaded with initial triad joint velocities Boundary conditions for dynamics analysis The additional boundary conditions that are defined in the triad property panel see Section 4 3 Triad properties are normally applied only during the initial static equilibrium analysis or also during the system eigenmode analysis However by specifying the following command in the triad description field DynBC Then the specified boundary conditions for that triad are also applied during the dynamics simulation and also in the eigenvalue analysis This is equivalent to attaching a constraining joint to that triad which also is attached to ground However using DynBCis a more direct and slightly more efficient way of applying such boundary conditions Fedem Release 5 0 User s Guide Index A absolute integration tolerances 6 20 active view 2 23 enlarge 2 24 reduce 2 24 scaling 2 23 active window controlling 2 8 ADAMS Car using with ADAMS Tire B 3 adder block 5 4 additional boundary conditions for triads 6 23 additional solver options 6 6 E 1 Align CS 3 10 Align rotations 3 10 Altair HyperMesh 1 4 amplifier block 5 4 amplifiers 5 4 analysis options management of 6 5 animation available results 7 29 control 7 32 loading performance 7 32 properties 7 23 Animation Control 7 36 Animation Control pane
461. tories 7 Once you have selected the file s and a unit conversion click Open The link files are imported and the coordinate system of the links are aligned with the global coordinate system When an FE model is imported it is converted to the internal Fedem format During this conversion several element groups might be created as well These element groups can either be user defined explicit groups or implicit groups based on the properties of the finite elements in the link F Function definitions Joints P Links 3 Bucket Ay 1 PTHICK A 1 PMAT amp p 2 PMAT amp p 11 Group Left wall ap i 2 Group Right wall All element groups associated with a FE link are listed in the Objects list in the Model Manager panel as illustrated to the right See Section 4 2 Element groups to learn more about element 4 Bell Crank groups in Fedem Eo Link S Reference planes Q Strain rosettes A Triads 4 1 2 Creating links from hard points If you only have the hard point information of a link you can create a link i from triads positioned at the hard points To do this follow these steps 1 Select some or all of the triads that represents the hard points of the link using the multi select features of Fedem See Section 2 5 3 Model Manager and Section 2 6 1 Select on how to select multiple objects either from the 3D Modeler Window or in the Model Manager Objects list 2
462. train coat recovery on element groups or individual links 6 43 6 9 6 Using nCode FE Fatigue eee eee cece cee Ie 6 43 6 9 7 Licensing needs cece cece cece eee n eect ene mmm een 6 44 Duty cycle analysis ag anaes etwas S E SRgd awed S ARS es 6 44 6 10 1 Getting started ers aar esee tx es y tuno urs Cub ens ees 6 45 6 10 2 Licensing needs i e ck eek et ur Se ee RE RHET 6 45 6 10 3 Setting up a Duty Cycleanalysis lessen 6 45 6 10 4 Running Duty Cycle cece cece cnn mene 6 46 6 10 5 Viewing Duty Cycle results 0 cece cece cece eee ene 6 47 Interaction during processing ccc cece cece teen ee eenee 6 47 6 11 1 Simultaneous viewing and processing ee cece teen eee e ees 6 47 6 11 2 Stop prOcesslng suse rever okie ERE Sae g s T ea dori ins eade 6 48 Deleting tesults ood dr har eR nr e ex Rer 6 48 6 12 1 Deleting specific results 0 ccc cece cece eee nnne 6 48 Automated curve export from multiple result database files 6 49 Batch execution of solver processes cece cece cence eenes 6 49 6 14 1 Batch solving trough the User Interface cece e eee e es 6 49 6 14 2 Preparing for batch solving on remote computers ussuuue 6 50 How to read error messages from the solvers suusuu 6 51 Postprocessing Results Postprocessing ENVIFONMENt cece cee cece eee ne 7 2 Graphis acea e oo teni RE du Pd pup de
463. tte options Fu To specify parameters for the strain rosette analysis click the Strain B Rosette Recovery Setup button on the Solvers toolbar or Solve menu You can specify the Start IDl x and Stop Time for strain E Time Interval rosette recovery and the D Time Increment at which to Stop m H recover the rosettes If the ncrement Jagd Use all time steps option is IF Use alltime steps enabled rosette recovery Bei will be performed for all com puted time steps e Direct export of gage strains to DAC files between the specified start DAC file sample rate f 0 001 and stop time The Reset Report cyclecount button restores the default EE Time Interval values which i are equal to the start and Q iportstrsinrosettefie stop times of the simulation as specified in the Dynamics OK Apply Cancel Solver Setup and using all time steps in between You may enable a direct export of gage strains to DAC files with a specified sample rate Q vou may enable a stress cycle count with a specified bin size The results are written to the file fedem gage res when running the strain rosette recovery The computed damage will also be reported to this file for all strain rosettes when this option is enabled Strain rosette definitions can be imported from a file by pressing this button The strain rosettes defined will then be read into Fedem and virtual strain rose
464. ttes will be created automatically based on the definitions See Section 6 8 4 Strain rosette definition file format for the format of this file Fedem Release 5 0 User s Guide 6 35 6 Mechanism Analysis 6 8 Strain rosette analysis 6 8 2 6 8 3 6 36 Starting the analysis Once you have set up the strain rosette recovery options and performed the dynamics simulation you can start the strain rosette recovery by clicking the Recover Strain Rosettes button on the Solvers toolbar or in the Solve menu Result output Results for all strain rosettes on a link are output to the binary frs file named lt linkname gt _ frs The frs file allows the post processing of strain rosette recovery results through graphs In addition to the stress and strain results you may also output the nodal deformations in the strain rosettes to the rs file by specifying deformationas an additional option to the Strain Rosette Recovery see Section 6 2 3 Additional solver options If enabled a file named rosette lt ID gt _gage lt n gt dac is written for each strain gage containing the strain of leg n in strain rosette ID This file is output in the nCode DAC format It is also possible to output the strain rosette result directly to ASCII files By specifying writeAsciiFiles as an additional option to the Strain Rosette Recovery you will get a file named rosette lt ID gt asc for each strain rosette defined A summary
465. ttings on the Eigen Modes tab shown below in the Property Editor panel before loading the animation This tab is not available for Time History and Time Summary animations Eigen Modes Mode Selection Frame Generation System modes I Frames per cycle 50 Time 0 0 Length C Time 0 Mode 2 No of cycl 1 Scale b 0 Tuy Until damped 190 Mode selection These options allow you to select the mode type time step or link mode number and a scale factor for the animation Select between System modes Component modes of link and Free free modes of reduced link from the first pull down list shown Time If you selected System modes this pull down list shows the times at which an Eigenmode solution is specified in the Dynamics Solver Setup see Eigenmode tab in Section 6 5 1 Link If you selected either Component modes of link or Free free modes of reduced link this pull down lists all links in the model It also have an entry All links to enable simultaneous link mode shape animations for all links See Section 6 3 6 Visualization of eigenmode shapes from the model reduction to learn more on link mode shape visualization Mode This pull down list shows either the modes specified in the Dynamics Solver Setup see Eigenmode tab in Section 6 5 1 7 28 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 3 Animations 7 3 3 Fedem Release 5 0 User the com
466. u EJ 2 Select the item s to detach hold down the Ctrl key while selecting multiple items in the Modeler window 3 Click Done to confirm your selection The object s are detached from your model NOTE When detaching a joint both the master and slave triads are detached If you want to detach only one of them press the Detach button then select the part of the joint symbol that represents either the master or the slave triad and press Done 3 6 6 Color of attached and unattached elements The color of a mechanism element indicates whether or not it is attached to the model If the element s symbol appears white the default color it is not completely attached A colored symbol indicates that an element is attached TIP The colors for attached and unattached elements can be changed in the General Appearance window see Section 2 7 4 General Appearance 3 6 7 Invalid attachments At some points Fedem may find that some Triads in your model does not correspond to an underlying i FE node even if it should have Fedem will then warn Hel you with a dialog box and mark all the invalidly attached triads with a red exclamation mark in the Model Manager Objects list Fedem Release 5 0 User s Guide 3 21 3 Mechanism Modeling 3 7 Deleting mechanism elements e The model will not be solvable as long as you have invalidly attached triads To resolve this you have several options Use a surface connector to conne
467. u want to expand and add them to the list of selected modal results Fedem Release 5 0 User s Guide 6 33 6 Mechanism Analysis 6 7 Mode shape recovery analysis E Mode and Time pull down lists ini xl with mode numbers and times at Select mode shape to recover which eigenmodes have been or Mode Time will be calculated in the dynamics 0o E analysis 2 Add Add button inserts selected mode o shape for the selected time into the Mode shapes to recover pee results list Mode Time 0 0 Q Mode shapes to recover list of selected mode shapes to expand e during postprocessing sorted by mode number RDOnMnN A o Delete button removes the selected mode and time from the results list gt x Automatic export to GLview VTF file 5 You may enable a direct export of a er h m GLview Express VTF file for each recovered mode shape for further dx OK Appl Cancel viewing in the Ceetron GLview oue pere pescar environment www ceetron com If a mode shape is to be recovered for more than one time step that shape will be exported to VTF only for the first time step specified Browse TIP The Mode and Time pull down lists both have an All entry in the bottom to facilitate easy selection of all entries in the list This is useful if you want to recover all mode shapes and or the selected mode shape for all time steps at which it has been computed N
468. ue to change the tick marks on the legend See also Tick marks in Section 7 4 3 Camera reference link When viewing an animation it is possible to make the camera follow the motion of a link in the model This is useful if some part of your model moves far during the simulation To do this selecting the link to follow in the Reference Link pull down menu in the Animation Control window Contour legend control Color mappings The drop down menu labeled Colors in the Animation Control dialog enables the selection of different color mappings for the contour values The different color mappings map the contour values differently This concerns values above within and below the legend domain They also show undefined results differently There are currently four color mappings available Full Color This is the default mapping and is a common way to display structural results Values Color Above legend domain _ Red Within legend domain _ Blue Cyan Green Yellow Orange Red Below legend domain Blue Undefined Gray Full Color B W Limits This is a mapping used to show what is within and outside the legend domain Values Color Above legend domain White Within legend domain Blue Cyan Green Yellow Orange Red Fedem Release 5 0 User s Guide 7 Postprocessing Results R 7 4 Viewing animations Values Color Below legend domain Black Undefin
469. ues below 0 01 meter are ignored If the road data has a fixed sample interval then the most accurate results will be obtained when ROAD INCREMENT is set equal to the sample interval of the road data In the example of Figure B 13 the value of ROAD INCREMENT is set to 0 1 meter the actual road data used in this example can be found in Section B 6 Road Property File Example B Using the SWIFT Tyre Model B 3 Force Evaluation m T Figure B 13 Filtering of Road Data Using Basic Functions Effective road example 0 03 T T T T T Road height m road profile O road data point basic function effective road 0 0 5 1 1 5 2 2 5 3 3 5 4 Travelled distance m B 3 7 Contact Model Residual Stiffness The contact patch is modelled as a body with mass and inertia and has three degrees of freedom longitudinal lateral and yaw motion as depicted in Figure B 14 The contact patch is connected to the rigid ring body of the tire belt with residual spring damper systems The slip forces are applied to the contact patch and the transient of slip forces is modelled following the relaxation length concept with an elaborate B model for the aligning moment calculation Fedem Release 5 0 User s Guide B 19 B Using the SWIFT Tyre Model B 3 Force Evaluation M Figure B 14 Contact Patch Model M wheel centre line TTA Va internal forces and moment MN AT Me seed F Moz
470. uide 6 Mechanism Analysis ET Chapter Mechanism Analysis Now that you can assemble a model and implement a control system you are ready to analyze the mechanism This chapter describes Fedem s methods of mechanism analysis and includes descriptions of setting up starting processing and stopping each analysis Sections in this chapter address the following topics Overview of Fedem analyses Solver tools Model reduction Model reduction in Nastran Dynamics analysis Stress recovery analysis Mode shape recovery analysis Strain rosette analysis Strain coat analysis Duty cycle analysis Interaction during processing Deleting results Automated curve export from multiple result database files Batch execution of solver processes VVVVVYVVVVVVVVYVY How to read error messages from the solvers Fedem Release 5 0 User s Guide 6 1 6 Mechanism Analysis 6 1 Overview of Fedem analyses 6 1 Overview of Fedem analyses 6 1 1 Model reduction To speed up the dynamics simulation and other mechanism analyses Fedem first performs the model reduction process During model reduction individual links FE models in the mechanism assembly are reduced to superelements with external nodes at those points which connect links and other mechanism elements Fedem uses a Component Mode Synthesis CMS model reduction method that replaces the internal nodal DOFs with a set of static and component modes The model r
471. ulation F 2 Links F 2 1 Geometric stiffness The Geometric stiffness contribution toggle in the Integration tab of the Dynamics Solver Setup dialog see Section 6 5 1 Dynamics Solver Setup applies normally to all flexible links in the model during the dynamics simulation It is possible to override this setting for a specific link using the following description field commands DynStressStiffening Enables geometric stiffness for this link NoDynStressStiffening Disables geometric stiffness for this link The commands affect the dynamics simulation only They have no effect during the initial equilibrium and eigenmode analyses They have no effect for generic parts with automatic stiffness calculation toggled on F 2 2 Component modes The number of Component modes that is entered in the Property Editor panel for a selected link defines how many component mode shapes that should be computed during the reduction of that link see Reduction Options tab in Section 4 1 4 Link properties Thus whenever you change this number the link might need to be reduced again The default is to use all the computed component mode shapes as degrees of freedom for the link during the dynamics simulation However it is possible to use Fedem Release 5 0 User s Guide F 5 F Beta feature documentation F 3 Springs F3 only a subset of the computed modes by specifying the following description field commands for the link InclMo
472. unction values are saved to the results database files for the computed time steps 4 10 4 Extrapolation For functions defined ona Parameters user specified finite domain the 0 00000000 10 00000000 option to extrapolate the function outside this domain exists i e functions of type Polyline Linear 0 10000000 0 00000000 A x 2 x af Extrapolation derivative or Spline The default is no mo p ae extrapolation None i Noe O Flat If the Extrapolation option is set to Flat the function retains the end point values when outside its domain That is 4 gt Forall v x the function evaluates to f x Forall v gt x the function evaluates to f x If the Extrapolation option is set to Linear the function is continued along the tangent line of the nearest end point that is gt Forall v x the function evaluates to f x v x Forall v gt x the function evaluates to f x x v x 4 10 5 Function Types All function types available in Fedem are presented in the following 1 1 This represents the identity function Its value equals the argument value Polyline This is linear interpolation between user specified points x y 7 v x fov Wr ce tae QX amp vEx QQ Xpypeie ln t i Fedem Release 5 0 User s Guide 4 53 4 Mechanism Elements 4 10 Functions To add many numbers to a polyline A function copy and paste is feasible i ra Copy the numbers from the I Oma o7 a
473. up wise solving to learn how such a process is started In this case strain coat elements are created automatically for the selected link s or element group s before the recovery process is started It is therefore no need to do this manually as explained in Section 6 9 1 Generating strain coat in this case 6 9 6 Using nCode FE Fatigue When nCode usage is enabled see Footnote 1 above an additional fpp file is created for each link during the Strain Coat analysis These files contains histograms over the maximum principal stress for S N analysis 6 or the maximum principal strain for E N analysis for each strain coat element In addition the following quantities are stored for each element The element number element type and element location The material group number Mean and standard deviation of the biaxiality ratio The biaxiality gate value constant for each link Most popular angle and angle spread The FPP file may be used in subsequent damage analysis in nCode FE Fatigue It is possible to launch FE Fatigue from the Fedem User interface Fedem Release 5 0 User s Guide 6 43 6 Mechanism Analysis 6 10 Duty cycle analysis ss In similar manner to launching Objects other solvers on specific links FE Fatigue is launched from the Solve menu in the right click pop up menu in the Model Managers Object list see illustration to the right Results Axial springs H F Function
474. ure and the motion of the tire relative to the road that is the amount and direction of slip The major control and disturbance forces on a vehicle arise from the contact of the tires with the road The vertical loads transfer the weight of the vehicle to the road Due to the compliance of the tires a vehicle is Fedem Release 5 0 User s Guide A 3 A Using the MF Tyre Model A 3 Tire Road Interaction A 4 cushioned against disturbances by small road irregularities The traction and braking forces arise from the longitudinal tire forces Lateral forces are required to control the direction of travel of the vehicle The lateral behavior of tires is therefore dominant in vehicle handling Proper description of the dynamic behavior of a vehicle requires an accurate model of the tire road contact forces and moments generating properties under all of these different conditions Figure A 1 Tire Factors Tyre factors Quasi steady state Vibratory state load carrying capacity radial deflection cushioning capacity braking driving performance longitudinal slip and dynamic coupling rolling resistance distortion lateral shift of Fz distortion destabilisation cornering performance lateral slip and phase shifts and primary effects interactions between secondary effects in and out of plane behaviour Tire behavior results from a combination of several aspects Factors may be distinguished which concern the primary tasks of t
475. ures listed here will be supported in a more permanent fashion in future releases Sections in this appendix address the following topics Joints Links Springs Frictions Tires Roads Additional masses Sensors Generic database objects Initial conditions for dynamics analysis Boundary conditions for dynamics analysis VVVVVVVVYVYVY Prescribed Triad motion Fedem Release 5 0 User s Guide F 1 F Beta feature documentation F 1 Joints F1 F 1 1 F 1 2 Joints Universal Joint The universal joint is obtained from the Ball Joint when the command UniversalJoint is entered in the description field of the selected Ball Joint The initial orientation of the joint cross is assumed to be the Y and Z axis of the Ball Joint master triad The Z axis of the cross is connected to the master link whereas the Y axis is connected to the slave link The user must thus reorient the master triad appropriately for the desired joint configuration Attention must also be paid to the selection of master versus slave link NOTE The universal joint has only two independent joint DOFs the Y and Z rotations Specifying a spring stiffness and or damping for the third DOF X rotation for this joint is therefore meaningless although that is possible in the property window Any such properties specified on this DOF will be silently ignored The same is true for initial conditions Constant Velocity Joint A Constant Velocity J
476. utton Opens a file dialog Reload button If your data source file has changed you can click this button to reload the curve into the viewer Channel field The name of the selected channel will appear here Only applicable for MTS RPCIII and multi column ASCII files Select button If you imported an MTS RPCIII or multi column ASCII file you will have to select which channel to extract data from A dialog for doing so will appear when clicking this button 00 Enable Fatigue You may chose to enable the Fatigue tab and run fatigue damage calculations on the loaded curve It is also possible to import multiple curves into an existing or new graph See Importing Curves and Importing Graphs in Section 7 2 13 Importing Curves and Graphs 7 12 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs Creating curves from a function A curve can be created from one of the functions defined in your model by selecting the nternal function option on the Property Editor panel s Data tab The panel used to define such a curve is shown below Data Fourier Analysis Scale and Shift Appearance Curve Statistics Source e s Em RDE Start x o0 Stop x o Increment 0 1 Auto Increment ntemal function Function None 2 z Incomplete Export curve automatically o Start x Stop x Increment Sets the end points for the domain to plot and the rate at which the function
477. view Slip force effects Q FCX Q FCY rd Residual mass inertia M_R I R i 1 C RP 1 K_RY T l eT Contact patch Wheel plane x Belt plane Wheel rim inertia M A I AY L AXZ h h CB C BGAM a A i 4 f 1 if K BY 1 K_BGAM CRY AWN Length Q_A1 Q_A2 FLT_A Effective inputs Q_LBF Q_LOS1 Q_LOS2 Q_LIMP Slip Q KCl Q KC2 Q AMIN Rear view Table B 8 Definition of Parameters in Tire Property File Tire parameter manual Tire naraek if appli notation pPlicable MODEL LONGVL Vo See Equation B 1 derived from Test Trailer measurement conditions ROAD INCREMENT n a Sample interval road data ROAD DIRECTION n a gt 0 driving in positive x direction lt 0 driving in negative x direction DIMENSION UNLOADED RADIUS hRg Fedem Release 5 0 User s Guide B 23 B Using the SWIFT Tyre Model B 24 B 4 Tire Model Parameters Table B 8 Definition of Parameters in Tire Property File Continued User i Notes Tire parameter m Tire characteristic if applicable SHAPE MF Tyre INERTIA MASS Mo Tire mass AY n a Value to be added to wheel rim multi AXZ n a Value to be added to wheel rim multi BY n a Tire belt moment of inertia about Y axis Belt wind up frequency gyroscopic effects BXZ n a Tire belt moment of inertia about X and Z
478. visual interpretation the mode shape is used to create an animation of the mechanism oscillating as if the eigenmode was excited The time displayed along with the progress bar shown during an eigenmode animation is the time elapsed during the oscillating motion The legend text displays the point in time for existence of the animated eigenmode during the dynamics solution Unless a mode shape recovery has been run you can only animate the rigid body component of the eigenmode for each link Note that the partitioning of the total mode shape into a rigid body approximation plus a deformable component depends on the chosen computational coordinate system of the link see Section 4 1 in the Fedem R5 0 Theory Guide In particular if the center of rotation for a mode is far from the origin of the link coordinate system the deformable component may be misleading However the sum of the deformable and rigid body components will always be correct Time Summary Time summary animations are used to show accumulated structural results within a specified time interval These results are produced by running the Strain Coat Recovery Summary and Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 3 Animations if available nCode FE Fatigue or Duty Cycle Examples of such results are the maximal principal stress reached within a time interval or damage accumulated within the same interval Usually only one frame with accumulated re
479. w of the rigid ring representation of the tire Figure B 1 Side View of the Rigid Ring Representation of the Tire Z rigid tyre ring rim longitudinal sidewall stiffness and damping rotational sidewall stiffness and damping vertical sidewall stiffness and damping vertical residual stiffness slip model road surface For the in plane behavior the stiffness of the springs is dependent on the in plane belt displacements rbx rbz and rotating speed W The influence of speed and load is implemented by using a correction coefficient Qv The correction coefficient is defined by Equation B 9 Q la Y Dig 7 B 9 The nominal tire belt stiffness for the in plane motions is corrected for deflection and speed in accordance with Equations B 10 and B 1 1 a ol qp vol Qy B 10 B 8 B Using the SWIFT Tyre Model B 3 Force Evaluation amp rtl dipsa Oy B 11 This results in a dependency of the belt stiffness on speed and load typically as displayed in Figure B 2 Figure B 2 Belt Stiffness for Various Speeds A Se X WE Y CS NS ARS WI SF The in plane forces and torque that are transmitted by the tire belt to the rim are given in Equations B 12 B 13 and B 14 Longitudinal belt force Fp Pork 29 2Kp psc B 12 Vertical belt force Fy 7 6 PozFz0 2KpyPocko B 13 Belt wind up torque Myy7 amp 4Pr0Cr0 2KygPbok o B 14 B 3 3 Out of Plane Cha
480. will therefore abort on any occurrence of singularities after the triangularization is completed All singularities found are then listed in the Output List and on the res file They are identified with the internal node number and the mechanism entity it is associated with Triad DOF Joint DOF or Link component mode 6 30 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 6 Stress recovery analysis 6 6 Stress recovery analysis 6 6 1 Stress recovery options To specify parameters for the stress analysis click the Stress Recovery Bh Setup button on the Solvers toolbar or Solve menu Each time stress recovery is run the results are added to the existing stress recovery results This means you could solve stresses for one time interval first and subsequently for another interval while stresses from both intervals could be animated in the same animation You could also solve stress first view them and solve strains later making both stress and strain available for post processing This also means that if stress recovery is performed more than once using identical settings the same results will be stored multiple times on disk It is not checked whether the results you asked for already exist or not o To specify the time steps at which stress is Stress Recovery Setup Eel xi recovered a Start time pas p Stop time and a time na Increment should be P provided However if the OH Use all
481. windows are described in the following sections TIP Windows in the Workspace can be managed using the Tile and Cascade commands from the Windows menu Modeler This window displays a 3D view of your mechanism and provides dynamic viewing capabilities such as zooming panning and 2 and 3 dimensional rotation see Section 2 7 1 3D Navigation The Modeler window is also used to view your animated simulation results Select this window to view create or edit a mechanism model To open the Modeler window select Show Modeler from the Windows toolbar or menu The Modeler is displayed as shown below See also Section 3 2 1 Modeler window 2 13 2 Learning the Basics 2 5 Touring the interface Modeler Reference Plane The shaded area in the center of the Modeler window represents a plane which can be considered the ground or base for your models Global Directions The arrows located in the lower left corner of the Modeler show the orientation of the global coordinate system and the direction of the gravity vector g cT TIP The Modeler window can be viewed at almost full screen size by hiding the Model Manager and Property Editor panels To hide these panels click the Model Manager and Property Editor buttons on the Windows toolbar or View menu Hiding the toolbars also increases the viewing area of the Modeler window see Manipulating toolbars in Section 2 5 1 ly Dos A a Control Editor T
482. x systems gt To start Fedem with a new empty model just type fedem at the command prompt gt To start Fedem and open an existing model type fedem f modelname fmm at the command prompt substituting lt modelname gt with the path and name of your model file When Fedem is started with a new empty model the model file is named untitled_ lt gt fmm where lt gt indicates a unique running number This empty model file will contain only some default settings animations and graphs The file will be created in your default login directory when Fedem is started from the windows desktop icon or Programs menu 2 4 Fedem Release 5 0 User s Guide 2 Learning the Basics 2 4 Starting Fedem B Command line options Fedem has several command line options that can be used to achieve different tasks These options can be invoked when starting Fedem from the command prompt See also Appendix E 1 Fedem UI Options fedem TIP You can create a new model file with a specific name by specifying a path and filename that does not yet exist using the option The file will be created for you and opened when Fedem starts 2 4 1 Template model file The default settings of anew model are stored in a template model file which is loaded whenever a new model is created either when Fedem is started or when using the New command see Section 2 8 3 Starting a B new model The template file can be modified or changed at
483. y analysis is currently based on the vector representation so that it will be twice as large as the equivalent quantity from the stress recovery analysis It is important to be aware of this distinction when using that particular result quantity Stress and strain range quantities The maximum stress and strain range quantities computed in the Strain Coat Recovery are derived from the principal value history at each point This computation is performed in a similar manner as for the Most popular angle and Angle Spread quantities That is the directions of the maximum and minimum principal values in terms of the in plane angle from the X axis of the stress coordinate system are used to divide the principal stress states into a discrete number of bins for each stress point The principal stress values at a certain time is then assigned to one such bin depending on its angle and the range for each such bin is computed as Fedem Release 5 0 User s Guide 7 31 7 Postprocessing Results 7 4 Viewing animations the difference between the highest and the lowest value over the whole time history The range value presented in the Time Summary animations is then selected from the bin having the largest computed range value 7 3 4 Performance of animation loading It is important to be aware that the performance of the animation loading is highly dependent upon the animation settings especially when working with large FE models 30 000 el
484. ynamics simulation Fedem may calculate an initial static equilibrium state for the mechanism model The static 6 2 Fedem Release 5 0 User s Guide 6 Mechanism Analysis 6 1 Overview of Fedem analyses pc n1 equilibrium analysis establishes a starting point for the dynamics analysis and eliminates the initial system transients such as the sudden effect of applying gravity or other external loads In the dynamics analysis such unbalanced forces in the initial configuration can generate undesirable effects such as vibration of the mechanism during the first time steps See the Fedem R5 0 Theory Guide Section 7 8 Quasistatic equilibrium for more information about the initial static equilibrium analysis The static equilibrium analysis determines a state for the system in which all internal and external forces are in balance in the absence of any system motions or inertial forces All system velocities and accelerations are set to zero during this analysis To set up the static equilibrium analysis see Section 6 5 1 Dynamics Solver Setup Dynamic Initial Conditions When using the static equilibrium analysis described above the subsequent dynamics simulation will start from a resting position with zero velocities and accelerations in all degrees of freedom In some cases however it is more relevant to start the dynamics simulation from a known velocity state at all triad and joint degrees of freedom instead Since Fedem R3
485. you Properties This frame contains the stiffness values for the manually selected stiffnesses Fedem Release 5 0 User s Guide 4 Mechanism Elements 4 1 Links When setting the stiffness calculations to Automatic Fedem uses the mass and a high target eigen frequency to calculate a sensible high stiffness This will work as long as the mass of the link is set to something sensible Thus Fedem is not able to calculate a good stiffness for a link with no mass at all or with a mass that does not correspond to the actual use of the link In such cases you will need to set the stiffness manually See the Fedem R5 0 Theory Guide Appendix A 16 Generic part element for details on how the Dynamics Solver derives a link stiffness matrix from the manually specified stiffness values Hydrodynamics tab This tab concerns the calculation of hydrodynamic forces on a link Part Origin CoG Mass Stiffness Hydrodynamics Advanced o Perform buoyancy calculations Buoyancy forces and associated load correction stiffnesses will be calculated based on the geometry defined in the specified Visualization file wrl or ftc and the water density Perform buoyancy calculation Enables the calculation of buoyancy forces for this link provided a link geometry and sea environment is defined See Section 3 9 3 Buoyancy Advanced tab This tab contains drop down menus for selection of positioning algorithm for the co rotated refe
486. you may select different standard S N curves to base the damage calculation on specify a time interval for the damage calculation and evaluate the equivalent life in days hours or 7 16 Fedem Release 5 0 User s Guide 7 Postprocessing Results 7 2 Graphs 7 2 11 Fedem Release 5 0 User repeats For details on how the damage is calculated from a given time history response see the Fedem R5 0 Theory Guide Data Fourier Analysis Scale and Shift Appearance Curve Statistics Fatigue Standard NorSok air 0 v S Ncurve B1 nA Stress range threshold 1 0 Results Life unit Repeats E Damage 2 428156e 007 Life Time Interval 5 Start 0 0 Stop 1 0 M Entire Standard Select the fatigue standard to use for your fatigue calculations s Ncurve Use the drop down to select a S N curve from the selected standard TIP The S N curve standards listed in the Fatigue tab are defined in the file sn curves fsn located in the installation directory of Fedem The syntax of the S N curve definitions is description in the header of this file and it is possible to add your own S N curve definitions to that file stress range threshold Stress ranges with magnitude below this threshold are ignored in the stress cycle counting rainflow analysis Damage Life Life unit The Results frame displays the damage results for the plotted stress history The life is displayed in days hours or repeat
487. you want then accept by pressing Done 3 Now you need to select all the FE nodes to be connected to the triad You can add single nodes to the selection by picking or all visible surface nodes within a rectangle by dragging a window If you press and hold the Ctrl key picked or window selected nodes will be removed from the selection instead of being added When finished press Done By cylinder surface These two commands crates a Surface Connector from nodes on the surface of a cylinder volume It is convenient to use them to attach a Fedem Release 5 0 User s Guide 3 Mechanism Modeling 3 6 Attaching and detaching elements pm M mechanism element to the inside of a hole a circular edge etc The command is also able to place a new triad along the axis of the cylinder making it easy to get the hardpoints This triad can then be used for further modeling The cylinder is defined by a 3 point circle together with points on each end of the cylinder To create a Surface connector by cylinder surface complete the following steps 1 Select either the rigid or flexible version of the command gt O0 T Xx 3x SiS we d b H maa Flexible surface gt e By cylinder surface XR Rigid surface gt QE By selecting nodes 2 First you have the option to select either an existing triad that will be attached by the Surface connector or a position where a new triad will be created If you rather want th
488. z Real Transverse shear reduction factors CX CZ Real Local y and z coordinates of the shear center of the beam PBEAMECCENT eid ex1 eyl ezi ex2 ey2 ez2 Parameter Value Type Description eid Integer Eccentricity vectors identifier ex1 eyl Real Eccentricity vector at local ezi node 1 of the beam ex2 ey2 Real Eccentricity vector at local ez2 node 2 of the beam PEFFLENGTH lid leff Parameter Value Type Description lid Integer Effective length identifier leff Real Effective beam length Fedem Release 5 0 User s Guide C FE Link Interface C 1 Fedem Technology Link format PBEAMPIN bpid pa pb Parameter Value Type Description bpid Integer Beam pin flag identifier pa Integer Local DOFs in end 1 that are released pb Integer Local DOFs in end 2 that are released PNSM nid rho flag Parameter Value Type Description nid Integer Non structural mass identifier rho Real The non structural mass per unit length if flag 0 and per unit area if 1ag 1 flag Integer Flag indicating if this entry is used by a beam or shell PTHICK gid t Parameter Value Type Description gid Integer Geometric property identifier t Real Shell thickness PBUSHCOEFF bcid ki k2 k3 k4 k5 k6 Parameter Value Type Description bcid Integer Bushing coefficients identifier ki Real Stiffness coefficients in local d

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