ATENA Example Manual
Contents
1. ATI NN eS 7 a ay 9 j 3 MRS j E T VS Reinforced Concrete 18 z B Cantilever1 u B Cantilever Figure 18 Display of the assigned material groups A composite material for the second part of the structure named as Cantilever2 can be defined in a similar way where the only difference is in the value of reinforcement ratio Figure 17 2 1 4 2 Bar reinforcement From the menu Data Materials we select the material Reinforcement which is designated for discrete bars There we choose from the list the ATENA model CCReinforcement and then click on the button New reinforcement and enter the name for the reinforcement material After confirmation by OK a dialog for material parameters appears The parameters include initial elastic modulus yield strength and optionally points on the stress strain curve The last parameter is the bar cross sectional area see Figure 20 The material is then assigned to the geometry by pressing the button Assign and selecting line geometric entities by the mouse The selected bars are marked by red color Figure 21 Applying the command Draw at the bottom of reinforcement material dialog see Figure 22 can check a correct assignment which shows the geometry in this case lines with the currently assigned material In case of pre stressed bars each bar cable must have a distinct material even if its values are identical with other2. kok k k k k k I ST ca ka SEI SE L Close Figure 57 Selecting results for postprocessing in GiD 48 The menu command ATENA GiD Post processing or the lt gt icon toggles GiD between pre and postprocessing A warning about non existent res file may appear then a console windows is started and the results are converted into a format readable by GiD see Figure 58 The conversion can take a few minutes depending on model size number of load steps and the number of quantities selected for postprocessing The results are stored into the AtenaResults flavia res file in the AtenaCalculation respectively AtenaTransportCalculation directory for static analysis respectively transport analysis This file can be opened in GiD by the File Open command see Figure 59 Gi Local LA N Y London Tokyo Moscow Delhi Singapore Sydney UTC m bq a o 2 Sg a 0o S Gt A My SNe w d Qo a x cx C WINDOWS system32 cmd exe Converting script res ATENA gt GiD S IM Im lt Vx RO amp RB EVE SN ODIO e me m L lz z y b File written to C amp tenaE xampless amp tena GID T utorial T emperature2D PipeBStatic gidN amp tenaR esults inp File written OK 1 Command Total Commander cc_seminar_2008_ cul Tutorial Atena Eng GiD 4 AtenaV4 Stat E Calculator cx CiAWINDOWS sys Figure 58 Importing results for post
3. Close Figure 54 Interval data for the interval 1 The stress analysis is again started by selecting the menu item ATENA ATENA analysis or the icon This starts the AtenaWin program The analysis is started Lem automatically or by clicking the button This starts the stress analysis in AtenaWin environment In order to visualize the development of the various data fields the button zm can be selected and this will open a dialog that is shown in Figure 55 In this dialog various variables can be selected for display The contour areas of crack width can be displayed by selecting Elements CRACK ATTRIBUTES CODI The resulting computer screen in shown in Figure 56 The imported temperature values can be displayed as ELEM TOTAL TEMPERATURE TotalTemp Please note that only the difference from the reference initial temperature is displayed in static analysis 45 lis London Moscow File Edit ter TO t RNIN Su AApRR U PNA Bos xXM WEB 50 0570Ww SAM 4 U e Le EE x B E Set 1 ConvergenceMonitor Seg LEGEND Geometry 0 7500000 5 Legend o Post processor data o 5000000 x E Available data General g v Draw output z A ELEM TEMPERATURE INCR uc IN ELEM TOTAL TEMPERATURE MaUx 0 ELEMENT ORIENTATION Location Max Us 576 006 EG PLASTIC STRAIN TE zh i FRACTURE_STRAIN Global nodes MmUy 0 0 2500000 MAXIMAL F
4. ERVENKA CONSULTING Cervenka Consulting Ltd Na Hrebenkach 55 150 00 Prague Czech Republic Phone 420 220 610 018 E mail cervenka cervenka cz Web http www cervenka cz ATENA Program Documentation Part 3 2 Example Manual ATENA Science Written by Vladim r ervenka Jan ervenka and Zden k Janda Prague January 6 2010 Trademarks ATENA is registered trademark of Vladimir Cervenka GiD is registered trademark of CIMNE of Barcelona Spain Microsoft and Microsoft Windows are registered trademarks of Microsoft Corporation Other names may be trademarks of their respective owners Copyright 2000 2010 Cervenka Consulting Ltd CONTENTS 1 CREEP ANALYSIS 1 1 1 1 1 112 1 1 3 1 1 4 Long term deflection of a reinforced concrete beam Introduction Comments on FE model preparation Results References 2 STATIC ANALYSIS 2 1 Zl 24 2 21 3 2 1 4 21 5 2 1 6 2 3 2 1 8 2 1 9 2 2 Z4 222 229 Example of a static analysis with reinforcement Reinforcement modelling Problem type and data Geometry Materials Supports and loading Meshing Monitoring points Load history Analysis and post processing Tutorial for Construction Process Introduction Geometry boundary conditions and load Running analysis 3 TRANSPORT ANALYSIS 3 1 3 1 1 3 12 313 3 1 4 3 1 5 3 1 6 Tutorial for Thermal Analysis Introduction Thermal Analysis Stress Analysis Postprocessing Conc
5. Figure 20 Material parameters for the Reinforcement model 19 20 Figure 21 Assigning material to the geometry of bars Reinforcement CC1DElastlsotropic Basic Miscellaneous Element Geometry Material Prototype CC1DElastlsotropic Young s Modulus E 2 1E 5 MPa Poisson s Ratio MU 0 3 Calculator R 1 To recalculate click Update changes next to material box 2x please Area 0 000201061 m HH Assign Draw Unassign Exchange CC1DElastlsotropic All materials A Figure 22 Display of the reinforcement material assignment 21 2 1 5 Supports and loading The supports and loading can be a specified using the menu Data Conditions We define the fixed nodes by checking X Y Z Constrains and the type of geometry Surface Using the command Assign we selects the end face of the cantilever and finish the assignment of support conditions In a similar way we assign the Point displacement at the node of load application The load is applied as a vertical imposed displacement Consequently the force value is a reaction at this node Conditions Constraint for Surface Basic Coordinate System GLOBAL iw Constraint iw Constraint iw Constraint Assign Entities Unassign Figure 23 Definition of the surface support in all directions Conditions Displacement for Point USE decimal peint DO NOT use comma ent 0 0 m A Displacem Displacem
6. 1 4 2 Postprocessing in ATENA 3D The highest user comfort for post processing 1s provided by Atena 3D After executing ATENA 3D the result file for each increment can be loaded into the program by using the menu File Open other Results by step This command activates a dialog that can be used to load ATENA binary files with results to ATENA 3D postprocessor When the user finishes loading the needed result file and closes the dialog ATENA 3D postprocessor is automatically started It should be noted that it is possible to open only binary result files that come from the same analysis For further details about post processing the user should consult the Part 2 2 of ATENA user s manual 2 3 1 5 Conclusions This tutorial provided a step by step introduction to performing combined thermal and stress analysis using ATENA software with GiD preprocessor The tutorial involves an example of an axisymmetric pipe heated from the outside from 25 to 37 C in 10 hours Then the heating remains constant for another 8 hours and is afterwards cooled back to 25 C in 6 hours ersion 51 The objective of this tutorial 1s to provide the user with basic understanding of the program behavior and usage For more information the user should consult the user s manual 2 or contact the program distributor or developer Our team 1s ready to answer your questions and help you to solve your problems The theoretical derivations and formulations tha
7. EO E Biss SN ks 7 N VOD NARS S LI ES X NBER ESE SPEEDO RAR SSSA ADAR ASA A MA NUS DAY NAY Conditions ERN Displacement 0 0 Entities Draw Unassign Point Displacement X Dis placement T Dic placement e e e I FESSES PSPSTEN DA E SO ER ET E m s mum mum L M y SS STS PRK AKASA AK L PE PK BOS R FS P P i k JS va V N ha Then the assigned condition value appears at the REACTIONS aint i feres z t P Ru ee ee 1 Po ira EAE RP SOA SME NY VSMS ELA T AA PSV kV MR S F A a ASN M LOH E TE KS S SE BS SNY ERIT SEPRU SOS UN y PE E VD VSV SS SUCUS A r Figure 31 View and inspect a condition in a mesh node h Fress Finish ta end selection Draw Each Iteration Monitor fo Output Data If we want to inspect the assigned values we can do it by clicking on the button Draw and select Field value Z Displacement concerned node See Figure 31 Analogically to the Section 2 1 5 it is also possible to specify the monitoring points directly on the finite element mesh The monitoring points are tools to record a structural response for select Force Monitor for reaction force Reaction Monitor for nodal displacement example a load displacement diagram In GiD we can for instance specify only force and displacement mo
8. Figure 36 Monitor for Point Monitor points Conditions Constraint for Point Dead Load Basic Coordinate System GLOBAL V Constraint V Y Constraint Z Constraint Assign Entities Draw Unassian Constraint for Point Colors All conditions Exclude local axes Field s value Only local axes Field s color b Include local axes Figure 36 Draw all conditons on model The construction should proceed as follows l excavation of a circular hole in the soil 2 adding lining ring 3 adding load First it 1s necessary to construct the model of the whole structure Three separate macro elements will be created for all four intervals Interval 1 this interval is used to define the basic boundary conditions to support the model from the bottom and both sides Interval 2 this interval is used for excavation of a circular hole in the soil by deleting two centered macroelements Interval 3 this interval is used to add lininig ring shape with concrete material characteric around the hole Interval 4 this interval is used to add load to top face of the model At the beginning the whole area consists of soil however we must define separate macroelements for future changes soil lining air We assign the soil material to all these macroelements for the first interval Figure 37 The additional intervals will be needed for the subsequent phases of the construction pro
9. aR aa TSE SE OAM a S ed ro Le EE s E Set 1 ConvergenceMonitor E X E CURRENT PSI VALUES at location NODES for item Temper Convergence criteria 1 4 CURRENT PSI VALL 5 9963132 Temper 33817 33688 33558 33429 44972348 333 33 17 33041 32912 32 782 2 9981566 Relative error Max U_x 0 Mm U x 0 Max U_y 0 Mm U y 0 1 4990783 Max U z le 010 Mm U z 16 010 Max X 21600 000 64800 000 86400 000 lt F PipeBTemp msg a fo x Iter Rel Humid Rel Temper Abs Humid Abs Temper Step 13 completed Elapsed CPU sec this step 1 672 all steps 20 857 Ka Ready Completed TE Time 8 6e 004 2 OVR 3 m job C win Sky amp Inb Sof GID a te are eed Gee ca Tut GID Figure 51 The runtime display of temperature field during the thermal analysis in ATENA After the thermal analysis is completed AtenaWin can be closed All resulting files are stored in the subdirectory AtenaTransportCalculation of the PipeBTemp gid directory In this subdirectory the following files will exist after the completion of the thermal analysis PipeBTemp inp ATENA input file created by GiD and used by AtenaWin PipeB 00xx Binary result files created by ATENA during the thermal analysis These two files are created in the Tutorial Temperature2D directory PipeB Results thw Saved temperatures to be used by stress analysis PipeB Geometry bin Saved geometry to be u
10. bars The reason for this is to distinguish among groups of elements for pre stressing The pre stressing is defined in Conditions Lines Initial strains and is assigned to the lines that model the pre stressing reinforcement New reinforcement IMain reinf Figure 19 New material for bar reinforcement n Reinforcement Main reinf 020 Basic Miscellaneous Element Geometry Material Prototype CCReinforcement Reinf 01 Young s Modulus E 2 1E45 MPa Reinf 01 Yield Strength YS 400 MPa Reinf 01 Number of Multilinear values 2 4 Reinf 01 eps2 Reinf 01 f2 Reinf 01 eps3 Reinf 01 3 Reinf 01 eps4 Reinf 01 f4 Reinf 01 eps5 Reinf 01 f5 Iv Calculator Profile Number of Profiles ecalculate click Update changes next to material box 2x please Area 314 15926535 mm Assign Unassign Reinforcement Main reinf o16 v ZB eS aX Basic Miscellaneous Element Geometry Material Prototype CCReinforcement Reinf 01 Young s Modulus E 2 1E 5 MPa Reinf 01 Yield Strength YS 400 MPa Reinf 01 Number of Multilinear values Reinf 01 eps2 Reinf 01 f2 Reinf 01 eps3 Reinf 01 f3 Reinf 01 eps4 Reint 01 f4 Reinf 01 eps5 Reint 01 f5 Iv Calculator Profile Number of Profiles R01 To recalculate click Update hanges next to material box 2x please Area 201 06192982 mm Assign Unassian X Enter new reinforcement name Exchange Exchange
11. copy operations can be selected such as rotation translation sweep There 1s also a check box which activates the extrusion VW AM Figure 11 Geometrical model 13 14 2 1 4 Materials The materials can be defined and assigned to the geometry using the menu item Data Materials Recommended procedure is to keep the default material unchanged for later reference and create any number of user defined materials Since we intend to model the vertical stirrups by smeared reinforcement we shall use the material type Reinforced concrete CCCombinedMaterial is a default material and Cantileverl Cantilever2 are user defined composite materials that are created from the default material by pressing the button O This command creates a new material of the same type which can be assigned a suitable user defined name see Figure 12 Reinforced Concrete FS Cantilever o nd o A x gt Basic Concrete Comp CCS mearedReint 01 LL SmearedR eint 02 Element Geometry Maternal Prototype CCCombinedMaterial iw Activate SmearedAeinf 01 i Activate SmearedReinf 02 Activate SmearedReinf 03 The smeared reinforcement components are activated using these checkboxes When selected new property sheets appear in the dialog Assign Unassign Exchange Figure 12 Reinforced concrete material Two composite materials created 2 1 4 1 Reinforced concrete as composite material First
12. division in lines of reinforcement In the item Quadratic elements we define low order elements by checking Normal In Structured define 1 division on lines Figure 29 In Mesh criteria select lines In Element types select Linear Lines 2 1 6 3 Mesh generation By selecting the item Generate the mesh is automatically generated The mesh can be inspected in the items Mesh view Mesh quality To change the mesh the whole process can be repeated GiD allows also changes by editing the mesh dimensions and properties 2 1 6 4 Assign conditions to mesh nodes Now if needed it is possible to assign additional conditions or materials directly to finite elements of nodes Select Data Conditions as shown in Figure 30 For this we must select by mouse the node where condition should be applied It is however recommended to assign the material properties and boundary conditions on the geometric entities rather then on the mesh otherwise it is necessary to reassign such properties every time the mesh is regenerated NSR Point Displacement 3 2 Displacement lia Y Displacement 0 0 z Displacement o 001 Assign Entities Draw Unassign Close Figure 30 Assigning condition of point displacement to a mesh node 26 Displacement 0 0 r Diisplacement 0 0 All conditions Fields color F This condition Colors ES
13. important to specify the M option in the command line when invoking the AtenaWin program This activates the creep module and various creep commands If the M option is not used various syntax messages are obtained 1 1 3 Results The results from the analysis are documented in Figure 6 where the calculated long term mid span deflection is compared with the experimental data obtained by Dr Vitek It shows that without any specific calibration the model predicts well the long term deflections 1 1 4 References 1 Atena Documentation Part 1 Atena Theory Manual Cervenka Consulting 2003 2 Atena Documentation Part 6 Atena Input File Format Cervenka Consulting 2003 3 Atena Documentation Part 8 User s Manual for ATENA GID Interface Cervenka Consulting 2003 Table 1 1 1 Material properties of concrete Material type a Creep material CCModelB3 oN O Thickness ie ratio of volume m to 0 05138 surface area m of cross section Cylindrical compressive strength f 46 75 after 26 days MPa Density kg m 2 370 kg Base material CC3DNonLinCementitious2 Elastic modulus GPa 34 200 MPa Compressive strength MPa 46 75 Tensile strength MPa 3 257 Fracture energy N m Compressive plast def m 0 0005 Table 1 1 2 Material properties of reinforcement Material type Reinforcement Elastic modulus 210 Yield strength perfectly plastic Table 1 1 3 Finite element mesh Finite element
14. three smeared reinforcements can be defined in one composite material This limit exists only in the GiD interface ATENA can define unlimited number of components for a single composite material in this case it is necessary to manually edit the ATENA input which is generated by GiD After the parameter definition the material can be assigned to the structure This 1s done by the button Assign and following the appropriate selection by mouse The process of selection is a 15 general operation and it allows for selecting of points lines surfaces and volumes In this case the material should be assigned to volumes of geometry Figure 15 Figure 16 Reinforced Concrete Cartiever z ZB gS x Basic Concrete Comp 0 CCSmearedReinf 01 CCSmearedReinf 02 Element Geometry Base Material Prototype CC3DNonLinCementitious2 YoungsModulusE 34E 4 MPa Poisson s Ratio MLI b2 Tension strength FT 218 MPa Compresion strenath FC 34 0 MPa MN Fracture energy GF 7 01 8e 5 p Fixed Crack 0 7 IV Activate Crack spacing Crack spacing 0 2 m v Activate Tension stiffening Tension stiffening 0 4 Plastic strain EPS CP 0 0009968 Onset of crushing FCO 7 0 MPa Critical comp disp WD 0 0005 m Excentricity EXC 0 52 Dir of pl flow BETA 0 0 MN RHO Density 0 023 Um m mE adt ma Assign Unassign Exchange Figure 13 Concrete component in the Reinforced concrete material Reinf
15. 0 x z Relative error Max U x 126 005 Mm U x Wax Uy 12e 005 Min U_y 0 0 2500000 Max U z 16 010 Mm U z 16 010 Mu X 12 Min X 0 Max 12 Min 0 Max Z le 010 Mm Z le 010 S S S Max Val 276 007 e e e s s s Mm WE 0 e e e e e e e lt e Sei i di F PipeBStatic msg mE Job Step 4 Log start 26 2 2009 12 30 50 Iter Eta Disp Err Resid Err Res bs E Energy Err NR Iter Eta Unbalanced Energy Ratio Current Required L3 1 uk 0 26 0 39 0 13 0 099 HR 1 1 0 82 0 8 LS 2 1 0 0076 0 32 0 11 0 0024 NR 1 T 0 85 0 8 LS 3 l 0 0095 0 27 0 094 0 0026 NR 1 1 0 86 0 8 LS 4 1 0 0079 0 23 0 082 0 0018 NR 1 1 0 86 0 8 LS 5 1 0 0068 0 2 0 072 0 0014 NR Ready Assembling Group 233 Elem 492 Time 4 6 OVR AE ARA ZZ n Figure 56 Execution process of stress analysis in AtenaWin showing the crack opening displacements After the completion of the analysis the AtenaCalculation subdirectory of PipeBStatic gid contains the following files PipeBStatic inp ATENA input file created by GiD and used by AtenaWin PipeBStatic 00xx Binary result files created by ATENA during the stress analysis 3 1 4 Postprocessing Postprocessing can be done either in AtenaWin GiD or Atena 3D Normally AtenaWin displays the current step that is analysed After the analysis is finished the last step remains in AtenaWin memory and can be visualized and further post proc
16. QV SRK RRR SSS AA SORIA KKK SA OK COA a a t dur dem EL nal FH mE S Figure 44 Numerical model finite element mesh The loading is subdivided in 3 intervals In the first interval 12 load steps are defined with boundary conditions as described in Figure 45 In each step the temperature on the outer surface is increased by C see Figure 45 The temperature in the exterior is 36 increased up to 37 C starting from the initial uniform 25 C Each step in this interval represents 3000 seconds thus the whole interval covers the period 0 36000 seconds 0 10 hours b Figure 45 Boundary conditions for the interval 1 In the subsequent interval 2 the temperature at the outer surface is kept constant This interval contains 10 steps 2880 seconds long This means the whole interval spans the time period from 36000 64800 seconds 10 hours 18 hours b Figure 46 Boundary conditions for the interval 2 37 In the last interval 3 the outer surface is cooled back to 25 degrees This interval contains 12 steps 1800 seconds long This means the whole interval spans the time period from 64800 86400 seconds 18 hours 24 hours b Figure 47 Boundary conditions for the interval 3 38 Problem Data E k amp Global Settings Time and Transport Restart Calculation from Calculated Step Title Fipe T askM ame Pipeb Method Displacement Error 0 0001 Residual Error 0 0001 Absolute Residual Erro
17. RACT STRAIN 37 Max U_s le010 NONE ement nodes Min U_z 1e 010 PERFORMANCE INDEX e PLASTIC STRAIN j Elements m 1 3 PRINCIPAL_FRACTURE_STRAIN Elements IPs PRINCIPAL PLASTIC STRAIN Y 12 PRINCIPAL_STRAIN Mm Y 0 PRINCIPAL STRESS Mex Zo 1e 010 RATE FACTOR Item Min Z 1e 010 RATE_FACTORS T SOFT H RD PARAMETER x STRAIN STRESS TENSILE_STRENGTH Cancel TOTAL ELEM BODY LOAD v m P eM ee pply puso 0 052 0 21 HR 2 1 0 014 0 017 0 0041 0 00023 NR 3 1 0 0011 0 0013 0 00032 1 4e 006 NR Step 1 completed Elapsed CPU sec this step 3 282 all steps 3 282 Job Step 2 Log start 26 2 2009 12 28 11 Iter Eta Disp Err Resid Err Res Abs E Energy Err NR Iter Eta Unbalanced Energy Ratio Current Required L3 1 1 0 5 0 11 0 026 0 054 NR d Ready Back substitution E Dof Blk 500 Time 2 2 OVR m Tutorial Atena Eng GiD Atenay4 Stat E Calculator AtenaWin JM CCS Figure 55 Execution of static analysis in AtenaWin and the selection of crack opening display 46 Tokyo Moscow Delhi Eber Sydney File Edi Tew IOO LIL DT duy FI operie TEE ml E Set 1 ConvergenceMonitor E E CRACK WIDTH at location ELEMENT NODES for item COD1 BE Convergence criteria 1 4 pa 1 0000000 CODl 2 7094e 007 23708e 007 20321e 007 16934e 007 13547e 007 1016e 007 0 7500000 6 7736e 008 3 3868e 008 0 0 500000
18. The temperature fields can be displayed by _ selecting CURRENT PSI VALUES Temper EIS London Moscow File Edit TTE Piru S EOD DT Oper ties CATO I SH PARR LOE NS BD suseg 3x 3 Z 55 Mx pH d RO 2 dB a m u Vo Le 2m E Set 1 ConvergenceMonitor Seg E Geometry PE Convergence criteria 1 4 5 9963132 4 4972343 L vo 9 29981566 m Available data General CURRENT NODAL COORDINATES Iv Draw output CURRENT PSI VALUES DISPLACEMENTS M 0 EXTERNAL FORCES Location acu 4 INTERNAL FORCES uU y NODAL DEGREES OF FREEDOM Global nodes MaUy 0 1 4990783 NODAL SETTING C El d Max zm 1e010 ement nodes MinU z le 010 PARTIAL EXTERNAL FORCES C Element PARTIAL INTERNAL FORCES A 3d PARTIAL REACTIONS C Elements IPs m PARTIAL RESIDUAL FORCES Y 3 Q_T m Y aw Z le 010 REACTIONS dMem 5 inZ le010 REFERENCE NODAL COORDINATES RESIDUAL FORCES s s s START PSI VALUES E 3 z amp ue eo i 2 Filter B PipeBTemp msg x Iter Rel Humid Rel Temper Abs Humid Abs Temper 1 0 1 7 0 6 2 o 9 1e 015 0 5 2e 014 Step 13 completed Elapsed CPU sec this step 1 672 all steps 20 857 v Ready Completed Time 8 6e 004 2 OVR Figure 50 The selection of temperature display in AtenaWin 41 5 for item Temper File Edi UTE Uu LIUIUS LU UL LI LT quy Prope LU Jui CIL uda ABP i SEIN G T A 3388 we HH HEB
19. cess 31 Figure 37 Material for interval 1 In next step excavation we need to remove both circles from the center It can be made using conditions for surface In menu Data gt Interval gt Current we switch to interval No 2 which we want to edit Figure 38 In menu Data gt Conditions gt Conditions for surface we choose Elements Activity for Surface and select Construction Elements Activity DELETE Figure 39 Next we can Assign areas which we want to excavate Figure 40 We can draw all macroelements which have assigned some conditions by choosing Draw gt Colors Figure 40 Enter value window Figure 38 Switching current interval 22 Conditions Elements Activity for Surface Using for Construction State for 20 Geometry except Shall L anstructien E lemients Activity DELETE Entities Unazsign Figure 39 Conditions for surfaces Conditions Elements Activity for Surface Using for Construction State for 2D Geometry except Shell Construction Elements Activity DELETE Assign Entities Draw Unassign cl Elements Activity for Surface Colors All conditions Field s value Field s color a DELETE CC3DNonLinC ementitious2 E 32666 HU 6 2 8 Figure 40 Deleting materials in interval 2 In the next step we need to create the lining with non linear concrete material We switch the current interval to No 3 In menu Data g
20. d The results of analysis can be presented in the program Atena3D The Post processing in ATENA 3D is started via menu ATENA ATENA 3D post processing Then it is necessary to import the binary result files TaskName xxx from the required load steps into ATENA 3D This is accomplished through the ATENA 3D menu File Open other Results by step For operation of AtenaWin Atena3D or any other details of ATENA software see the ATENA Documentation 29 2 2 Tutorial for Construction Process 2 2 1 Introduction The objective of this tutorial is to show how the graphical environment of GID can be used to model the construction process The finite element solution core of ATENA supports the possibility to add or remove groups of finite elements This feature can be used to model the construction process in GID The ATENA GiD extension of the GID graphical environment includes direct support for this feature This feature can be modeled using the conditions for surface and it will be demonstrated in this manual on the example of a tunnel see Figure 35 Soil Lining Soil Air Figure 35 Model with three macro elements The basic idea of the construction process modeling in ATENA is the following It is possible to add or remove finite element groups at any time 30 2 2 2 Geometry boundary conditions and load We need to analyze a structure of a tunnel Around the tunnel there is concrete lining Boundary conditions are seen in
21. eated in such a way to facilitate the generation of purely structural meshes 1 e meshes that are composed of only quadrilateral and hexahedral elements in 2D and 3D respectively 1 1 2 1 Reinforcement If program GID 1s used for pre processing the reinforcement can be modeled in two ways smeared reinforcement can be modeled by Reinforced Concrete material or by discrete bars Discrete reinforcement bars are modeled as line curves These lines should be meshed by as few elements as possible Typically one truss element per line is sufficient ATENA then automatically determines the intersection of these lines with the 3D model and places reinforcement embedded elements into each segment that is created by this process 1 1 2 2 Materials When creep analysis is requested the material for which creep should be taken into account must be modeled by one of the creep materials see the Atena Theory Manual 1 or Atena Input File Format 2 Within the creep material a base concrete material is defined which is one of the standart ATENA materials Currently only following materials are supported as creep base materials CC3DNonLinCementitious2 CC3DbiLinearSteelVonMises Or CC3DDruckerPragerPlasticity Material properties used in this example are listed in Table 1 1 1 and Table 1 1 2 1 1 2 3 Topology and loading The loading history is defined in terms of intervals in GID In the first interval the supports are defined as well as the two vert
22. ent 0 0 m Displacement 10 0005 m Assign Entities Draw Unazsign Figure 24 Definition of prescribed displacement in vertical direction The conditions dialog of GiD can be also used to define ATENA monitors These are special type of conditions that does not affect the analysis results They are merely used to monitor certain quantities during the analysis In this example the following monitors will be specified e Maximal crack width e Displacement at the point of load application e Reaction at the point of load application The definition process of the above conditions and monitors is described in Figure 26 The resulting assignment of the boundary conditions can be checked using the command Draw All Conditions Exclude local axis which can be located at the bottom of the Conditions dialog It should be noted that it is also possible to apply these conditions directly on the generated finite element model but then the applied conditions are lost every time the mesh is regenerated 22 Conditions a A d A MaxM onitor for Volume Data Attribute CRACK WIDTH ltemAt al Global MM MAXIMUM Location NODES Draw Each Iteration Assign the crack width monitor to all volumes W IdentificationByName MonitorName MaxCrag Assign Entities Unassign Conditions Monitor for Point Output Data DISPLACEMENTS M Dix DirY lv Diz Draw Each Iteration Mo
23. essed In case the user wants to post process results from other load step the corresponding step results file is to be opened using the command Application Restore FE Model From The step data file name is task name 00xx where task name 1s the name of the current task as given in the problem data dialog see Figure 53 and 00xx represents the load step number which 1s to be post processed 47 Alternatively the new text window is to be opened using the menu item File New Please note that a text window must be highlighted in order to another text window If graphical window is the active one a new graphical window will be opened Into the new text window the following command shall be written RESTORE FROM task_name 00xx 3 1 4 1 Postprocessing in GiD To be able to postprocess the results in GiD the result quantities must first be made available by selecting them in the Data Problem Data Post Data dialog see Figure 57 Post data x DISPLACEMENTS PARTIAL INTERNAL FORCES INTERNAL FORCES PARTIAL EXTERNAL FORCES E TERNAL FORCES PARTIAL REACTIONS REACTIONS FARTIAL RESIDUAL FORCES RESIDUAL FORCES PHYSICAL PARAMETERS STRAIN PRINCIPAL STRAIN STRESS PRINCIPAL STRESS TENSILE STRENGTH FRACTURE STRAIN PRINCIPAL FRACTURE STRAIN MAKSIMAL FRALT STRAIN CRACK WIDTH PERFORMANCE INDE PLASTIC STRAIN PRINCIPAL PLASTIC STRAIN SOFT HARD PARAMETER EQ PLASTIC STRAIN REFERENCE NODAL COORDINATES M MEME NI
24. ical forces The first interval should represent the application of the permanent load In the subsequent interval this load will be kept constant and the material will creep causing the deflections as well as cracking increase The application of the permanent load is expected to cause some cracking therefore it is subdivided in 20 steps The application of the permanent load will start at the time of 63 days and it will be completed at 63 02 days In the second interval no additional forces are applied therefore only supports are defined for this interval The interval starts at 63 02 days and continues up to the stop time 1 e 365 days defined in Data Problem Data This interval is represented in ATENA by only a single step ATENA automatically inserts substeps if it determines that one load step would not be sufficient for such a long time period Monitoring points Monitoring points are chosen in order to describe a load displacement response as well as the long term behavior In ATENA GID interface the monitoring is defined as conditions Data Conditions The monitoring defined in this way is considered only if specified in the first interval The definition of monitoring points in subsequent intervals is ignored In this example always the applied force is monitored as well as the mid span deflection Run Analysis can be started either directly from GID or by typing the following command oAtenaWin M CCStructuresCreep It is
25. is to enter the number of repeated load steps and multipliers in the window of Interval Data Figure 34 which is a proportional load history In case of a non proportional history for example first a vertical load followed by a horizontal load we can use Data Interval Data Default settings of calculation method and global settings are in Data Problem Data 28 Interval Data fi ES LOAD NAME Load LOAD STEP Multiplier f al Store data for this IntervalSteps SAVE ALL Iv Generate Multiple Steps Number of LOAD STEPs 50 All conditions will be multiplied by a factor 1 0 in all load steps generated in this interval Results from all steps will be saved Each step is saved in a separate file which is named TaskName xxx where xxx denotes the step number n 50 load steps will be generated All with the same conditions INTERVAL STARTING TIME 0 0 day INTERVAL END TIME 0 04 day perature LO 50 These data fields are editable only the import of transport data is requested in Problem Data User Solution Parameters dialog Close Figure 34 Interval data definition 2 1 9 Analysis and post processing The non linear analysis is started by the menu item Calculate or icon B This causes the data from GiD to be written into an input file for ATENA INP and the program AtenaWin is started During the execution of AtenaWin variety of intermediate results can be viewed and inspecte
26. lusions Literature ii SINAN Ul 10 10 10 17 13 14 21 24 26 Z 28 29 29 30 34 34 34 34 42 46 50 52 1 CREEP ANALYSIS This chapter contains examples of creep analysis using the program ATENA Currently the commands required for creep analysis are not supported by the native ATENA graphical environment and therefore the necessary commands must be entered manually or by using the ATENA GID interface GID see the Internet address http gid cimne upc es is a general purpose finite element pre and post processor that can be used for data preparation for ATENA See the README TXT file in the ATENA installation for the instructions how to install the ATENA interface to GID In order to activate the creep analysis option an appropriate problem type must be selected Data Problem type AtenaV4 Creep 1 1 Long term deflection of a reinforced concrete beam Keywords reinforced concrete discrete reinforcement creep Input files EXAMPLES GID CREEP2D VITEK2D GID EXAMPLES GID CREEP3D VITEK3D GID 1 1 1 Introduction This example demonstrates the application of ATENA system to the creep analysis of a reinforced concrete beam The analyzed beam was tested by Dr Jan Vitek from Metrostav corp Czech Republic 1 1 2 Comments on FE model preparation General data The problem is modeled by two models two dimensional one and three dimensional In both cases the geometrical model Figure 2 and Figure 4 is cr
27. nce the smeared model of stirrups does not exactly represent their geometry it 1s alternatively possible to use discrete bars as well This 1s case is not described in this manual but it can be found in the data file Demo L Bars 2 1 2 Problem type and data Typically Both steps were already described in Chapter 4 However the the menu item Data Problem type Atena V4 Static and then the general solution data in Data Problem Data parameters of Problem Data can be also changed later 2 1 3 Geometry The geometry is created by using the GiD graphical tools from elementary objects sequentially starting from points lines and finally surfaces and volumes We start with the definition of points Points are connected to lines From lines we can form surfaces and from surfaces we can form volumes solid objects Details of this input shall be skipped since it belongs to standard GiD functions The final geometrical model is shown in Figure 11 Note that it contains two types of objects volumes for concrete and reinforced concrete and lines for the discrete reinforcement In GiD it is also possible to create volumes directly from predefined primitives as shown in the figure on the right which indicates the available list of predefined primitives such as rectangle circle sphere etc The volumes can be also created by extrusion which is activated from the GiD menu Utilities Move or Copy In this dialog various
28. nitorN ame DisplZ p Assign the displacement monitor to this point gt f i R TON Hi SHY Assign Entities Draw Unassign se NS 65 NN INS AJ Conditions M Monitor for Point REACTIONS Output Data I Dirx DirY Iv Diz Draw Each Iteration Assign the reaction monitor to this point Assign Entities Unassign Figure 25 Definition of the ATENA monitors 23 GiD AtenaV 3 Static3D Interface Project Demo L RC ODO 99 Sa c 9 amp Dil Versions HN i Applied displacement and two monitors for deflection and reaction monitoring H1 S IN A a a EIL Ni NEN Use Draw All Conditions Exclude local axis to display conditions Pick LEFTMOUSE to desplace view ESC to quit Al pi ji e to leave api lea E Comman d EH Figure 26 Display of assigned conditions In certain cases it may be advisable to manually identify which line entities represent reinforcement By default the GiD ATENA interface attempts to treat all lines that are not connected to any surface or volume as reinforcement This default behavior is activated by the corresponding check box in the Problem Data dialog In certain cases the automatic identification does not work properly In this case it is advisable to deactivate this defa
29. nitoring at a mesh node This is done also in Conditions For applied force we Displacement Monitor Displacement component is selected by checking the appropriate box 2 1 7 Monitoring points Figure 32 Definition of a monitor for reaction at node 27 Ls d V Ay Vinal oer P p ET SNP UNE MAAZA Output Data DISPLACEMENTS RS AL pet Ir PELIS HL T LE E ZL doc OE EE Dir Z A PLAT med PRA Draw Each Iteration A N HTP DTA 2 Finish Press Finish to end selection CE 7 X J Peo FTP Va Un ET s Figure 33 Definition of monitor for displacement at node Figure 32 and Figure 33 show definition of force reaction and displacement monitors at a node An inspection of monitors can be done by the command Draw in the same manner as in other conditions The monitoring points must be included within Conditions of the first load interval in GiD Monitors included in other intervals will not be active in ATENA analysis 2 1 8 Load history For analysis in ATENA a load history as a seguence of load steps must be defined The load steps can be proportional or non proportional In this example the load history is simple We define first interval which includes a set of conditions for supports at the fixed end and point displacement This can be checked and changed in the menu item Data Interval Data Next load steps can be done in two ways The simplest way
30. nserting before the names writes them into the Tutorial Temperature2D directory The ATENA calculation is started from the menu ATENA ATENA analysis or by clicking the calculator icon CI This will start AtenaWin program which is a graphical interactive environment for the execution control of ATENA finite element core module More details about the usage of this program can be found in the corresponding ATENA manual 5 After executing ATENA analysis the following window appears on the user s computer see Figure 49 File Edit mew Wido x Dur Draw PTOPETUES DUICGUU 1121 ia eee ae 9 A Sah eus d we EB SAR S39 xw Gp EE am CAA 4 u e Le H Bb E Set 1 ConvergenceMonitor X E Geometry SEE Convergence criteria 1 4 Relative error VP PipeBTemp err ATENA Version 4 1 3 2241 c Cervenka Consulting 1998 2008 Load step 1 at time 6000 Ready Assembling Stiffness Internal Forces Group 463 Elem 204 Time 6e 003 1 OVR s 6 Sto G win B sky amp Inb Figure 49 The main AtenaWin window after its activation from GiD The ATENA analysis is started automatically or by clicking the button This starts the thermal analysis in AtenaWin environment In order to visualize the development of the temperature field the button sm can be selected and this will open a dialog that is shown in Figure 50 In this dialog various variables can be selected for 40 display
31. of stirrups In smeared model the exact position of individual stirrups is not captured and only their average effect is taken into account The resulting model is shown in Figure 8 The colours of elements show two types of materials used the composite material named Cantileverl in the short beam and Cantilever2 in the longer beam The discrete bars are modelled by linear elements as shown in Figure 9 In the following we Shall treat the generation of the model in more details A data file with this example can be found in the ATENA installation under the name smallCantileverWithTorsion DiscreteBars gidTutorial Static3D in the subdirectory Atena Examples Tutorial Static3D Section A Section B Figure 7 L shaped cantilever beam Dimensions in mm E Cantilever1 I Cantileuer2 B Hain Reinf Figure 8 The model with two composite materials Cantilever 1 and Cantilever 2 12 J ASRS Ao P PEN S VVN a e k i 11T pm ee STK KKL KOS SS STN M EI 1 d L pling F FT LAE E RM SL LESE ERU SESS K r I 1 pei i UNTAN EAS AAAS d SU NTN SECTEUR E Vt ee Sp Ai i nA CATAL AAT E gid enclosed in the ATENA installation finite element model with supports and loading Figure 9 The model of the discrete bars Figure 10 Final the problem definition starts by choosing an appropriate problem type by selecting si
32. on for volumes concrete First we shall deal with the meshing of volumes concrete There are many ways how to define mesh In this case we use a simple method in which divisions on all lines are defined If opposite lines have the same division we can create a regular mesh e In the item Quadratic elements we define low order elements by checking Normal e In Structured we define division on all lines It is always sufficient to select one line GiD automatically assigns the same division to all opposite edges e In Mesh criteria we select lines e In Element types select Hexahedra 2 1 6 2 Mesh definition for lines reinforcement It is important to realize that lines of reinforcement in GiD serve only to export geometry to ATENA The embedded reinforcement will be generated in ATENA This means that we should make the line elements of reinforcement as large as possible If we use division into a single element then this single element is then passed to ATENA for the generation of the individual bar segments Finding the intersections of the reinforcement bar with the solid elements generates the segments In case the reinforcement in GiD 1s modelled using curved lines then it is recommended to prescribe a certain division to finite elements such that the curved geometry of the bar is properly represented 25 Enter value window X Enter number of cells to assign to lines Figure 29 One
33. orced Concrete Cantiever e e X Basic Concrete Comp 0 CCSmearedReinf 01 CCSmearedReinf 02 Element Geometry Reinf 02 Material Prototype CCSmearedReinf Reinf 02 Young s ModulusE 2 1E 5 MPa Reinf 02 Reinforcing RATIO pz amp s Ac ja 0025 Reinf 02 Dir x of the smeared reinf ooo Reinf 02 Dir Y of the smeared reinf E Reinf 02 Dir Z of the smeared reinf p Reinf 02 Yield Strength YS 400 MPa Reinf 02 Number of Multilinear values 2 Reinf 02 eps2 0 2 Reint 02 f2 400 MPa Remnf 2epsaD Reint 023 0 MPa Reif 2epsd D Remt 2HM 0 MPa Renf 2epss Reint 025 0 MPa MN Reinf 02 RHO Density ja 0785 mg m Reinf 02 Thermal Expansion Alpha Jo 000012 8 Assign Exchange Figure 14 Components of smeared reinforcement in the composite material 16 Reinforced Concrete X Cantilever v ZB ES 2X k 2 Basic Concrete Comp 0 CCSmearedR einf 01 CCSmearedR einf 02 Element Geometry Material Prototype CCCombinedMaterial IV Activate Concrete Comp C v Activate SmearedReinf 01 Iv Activate SmearedReinf 02 Activate SmearedReinf 03 Assign Draw Unassign Exchange Points Li Close ines Surfaces Figure 15 Menu item Assign Volumes 9 AN lS d SSES A p Figure 16 Selected volumes are highlighted by red colour 17 i i p UN LAL Sy a Figure 17 Assignment of the material Cantilever2
34. processing in GiD 49 DY gi ose i oc LE A5 Syke d mH 4 d ET 9 pE 4X So MI ES Ii I 4 4 9 Ux d Postprocess Read Directory SJ AtenaCalculation f E AtenaResults flavia msh Eia EN ha S A Skew a NF ENS HE HO XI L File name AtenaResults flavia res Open Files of type GiD postprocess res msh bin E Cancel y b File written OK E Enter name of file to read E Command Total Commander 7 0 cc_seminar_2008_09 cu Tutorial Atena Eng Te GiD AtenaV4 Static E Calculator Figure 59 Opening results for postprocessing in GiD The results can be then postprocessed Figure 60 shows crack width as contour lines which can be selected by the menu command View results Contour lines CRACK WIDTH CODI The command can also be accessed from the S icon 50 m ISB Coa SSO 3 g e s oi 95 UE o 8 amp X a x di IIS Im ONS e I E oF NF LEV T YY 91514869 gk zz NM p m FADO XML COD1 1 66e 05 6711e 05 A622e 05 2933e D05 4446 05 3556e D6 2667e 06 1776e 06 0889e D6 RABI CELLA ONA DO gt gt gt b x step 50 Contour Lines of CRACK WIDTH COD1 Contour Lines CRACK WwIDTHI Min 0 Max 1 88e 005 Contour Lines COD1 Min 0 Max 1 88e 005 Figure 60 Displaying crack opening displacement isolines in GiD 3
35. r 0 0001 Energy Error 0 000001 Iteration limit 30 Optimize width Sloan Stiffness type Tangent Fredictor Assemble Stiffness M atris E ach Iteration Solver LU Extend Accuracy Factor Line Search Method Conditional Break Criteria Step Stop Displacement 100000 Iter Stop Displacement 100000 Step Stop Residual 700000 Iter Stop Residual 700000 Step Stop Energy 100000 Iter Stop Energy 100000 Master Slave Distance 1 0E 4 Extrapolation Nearest IP Show Surface Loads In Post Processor Write Monitor Data Close Problem Data Global Settings Time and Transport Restart Calculation from Calculated Step Time Integration of Transient Theta of Crank Nicholson 0 7 Iw Export Transport Results Export Results Ta PipeB He Export Geometry Ta FipeB Gier Close Figure 48 Problem data dialog induding the definition of temperature exchange files with stress analysis The problem data dialog that 1s shown in Figure 48 can be opened via the menu item Data Problem data This dialog can be used to define the basic parameters for the 39 thermal analysis The most important fields can be found at the bottom of the Time and Transport tab where the names of two files are to be specified These files are used for exchanging the temperature fields with the subseguent stress analysis By default the files would be stored in the AtenaTransportCalculation subdirectory of the main problem directory i
36. r data preparation and mesh generation The programs GiD and ATENA can be installed using the standard ATENA installation At the end of the installation the user must select the installation of GiD and ATENA GiD interface After that your computer should be ready to run the example problem described in this document 3 1 2 Thermal Analysis First the program GiD is started The recommended version is 9 0 4 or newer the oldest supported version is 7 7 2b After starting GiD the user should open the example analysis ATENA Science ATENA GiD Tutorial Temperature2D PipeBTemp gid This 1s an existing model demonstrating the combination of thermal and stress analysis This problem 1s using the problem type AtenaV4 Transport It represents a section of a pipe wall with thickness of 0 23 m and internal diameter of 1 m Taking advantage of the symmetry only a quarter of the whole crossection is modeled The geometry of the model is shown Figure 43 and the numerical model 1s shown in Figure 44 Details about ATENA GiD interface and associated problem types for ATENA can be found in the manual 6 The same mesh size is used for thermal and static analysis This is however not a strong requirement The thermal loading can be exchanged also between models with totally different meshes 35 b Figure 43 Geometry and material properties of the axisymmetrical pipe model EEE EEE ER RAAT EEE RRS OEE ARES R RRR O R Z x ROK RX K BERRY LER R
37. rch With Iterations Line Search ith Iterations Unbalanced Energy Limit 0 8 Line Search lteration Limit 33 Pirimum Eta 0 1 Maximum Eta 1 Conditional Break Criteria Close Problem Data Global Settings Global Options Transport Restart Calculation from Calculated Step iw Import Transport Results Import From Results PipeB He Import From Geometry PipeB Het Close Figure 53 Problem data dialog including the definition of temperature exchange files The loading history 1s specified in a single interval The interval is divided into 50 load steps In each step the temperature difference of 720 seconds from the thermal analysis 44 is applied Figure 54 So the interval spans the period of 10 hours 1 e it only covers the heating phase The Transport Import switch set to Interval Beginning means the thermal analysis results are only imported once and the temperature values are interpolated for each static analysis step For complex temperature histories it can be changed to Each Step Interval Data Basic Parameters Eigenvalue Analysis Iw Interval ls Active Load Mame temp load Interval Multiplier 1 0 Number of Load Steps 50 Store Data for this Interval Steps SAVE ALL Fatigue Interval ML iw Read Transport Data Transport Import INTERWAL BEGINNING Interval Starting Time 0 hour Interval End Time 10 hour W Delete BC Data After Calculation User Solution Parameters
38. sed for the interpolation of temperatures in the stress analysis 42 3 1 3 Stress Analysis After the thermal analysis is completed AtenaWin can be closed and the stress analysis can be performed using the calculated thermal fields A new GiD problem must be created or the existing problem PipeBStatic gid can be used This model defines the input for stress analysis of the same pipe wall as was used in the thermal analysis The geometrical model and boundary conditions are shown in Figure 52 Figure 52 Geometrical model and boundary conditions for stress analysis In order to be able to utilize the thermal fields calculated during the thermal analysis the appropriate import files must be specified in the problem data dialog that is activated from the menu Data Problem data and is shown in Figure 53 This information 1s located in the bottom 2 input fields where appropriate file names are specified including their path 43 Problem Data Global Settings Global Options Transport Restart Calculation from Calculated Step Title demo default title for Static analysis Task ame Pipeb Static Method Newton Aaphson Displacement Error 0 01 Residual Error 0 01 Absolute Residual Error 0 01 Energy Error 0 0001 Iteration Limit 60 Optimize B and width Sloan Stiffness Type Tangent Predictor Assemble Stiffness Matis Each lteration Solver LU Extend Accuracy Factor iw Line Search Method Line Sea
39. t Conditions gt Conditions for surface we choose Elements Activity for Surface and select Construction Elements Activity CREATE WITH NEW MAT Figure 41 and choose the CC3DNonLinCementitious2 material We can create specific material for this case and assign to surfaces which we want to create Figure 42 33 Conditions Elements Activity for Surface Using for Construction State for 30 Geometries without Shell L anstruction E lements Activit CREATE WITH NE MAT Assign material material for linning Entities Unassign Figure 41 Condition for surface create new material E CREATE WITH NEW MA T CC3DNonLinCement itious2 E 34288 Figure 42 Creating concerete lining In the last step Interval No 4 we will only add load to top of the model Data gt Conditions gt Conditions for line Load for line 2 2 3 Running analysis Analysis can be run by selecting button in menu Calculate gt Calculate or clicking on the button D Atena Calculate and in Atena Win by clicking on button Execute 34 3 TRANSPORT ANALYSIS 3 1 Tutorial for Thermal Analysis An example demonstrating the coupling of thermal and stress analyses 3 1 1 Introduction This document describes an example of rotationally symmetrical vessel subjected to thermal loading The analysis is performed using the programs ATENA and GiD ATENA is used for thermal and static analysis and the program GiD is used fo
40. t are used 1n the program are described in the theory manual 1 Experienced users can also find useful information in the manual for the analysis module only 4 52 3 1 6 Literature 1 ATENA Program Documentation Part 1 ATENA Theory Manual CERVENKA CONSULTING 2009 2 ATENA Program Documentation Part 2 1 and 2 2 ATENA 2D and 3D User s Manual CERVENKA CONSULTING 2008 3 ATENA Program Documentation Part 3 ATENA 2D Examples of Application CERVENKA CONSULTING 2005 4 ATENA Program Documentation Part 6 ATENA Input File Format CERVENKA CONSULTING 2009 5 ATENA Program Documentation Part 7 AtenaWin Manual CERVENKA CONSULTING 2008 6 ATENA Program Documentation Part 8 User s Manual for ATENA GiD Interface CERVENKA CONSULTING 2008
41. type CCIsoQuad CCIsoBrick Quadrilateral Hexahedral isoparametric isoparametric Element shape smoothing N A Gibbs Poole Gibbs Poole Table 1 1 4 Solution parameters Number of iterations 60 Prost nosn k AaB Pohled V ztu 4xo10mm 10505 R Kryt 30 mm Zat en F 6 9 kN Figure 1 Geometry of the reinforced concrete beam Figure 4 Three dimensional geometrical model with reinforcement loading and boundary conditions in GID Figure 5 Three dimensional finite element model 10 UJ DJ U NO Cn Vitek2D Vitek3D Experiment A Experiment B Total middle deflection mm U 0 60 90 120 150 180 210 240 270 300 330 360 Time days Figure 6 Long term mid span deflection Comparison of two and three dimensional analysis with experimental data 2 STATIC ANALYSIS This chapter contains examples of static analysis using the program ATENA Currently some commands required for static analysis are not supported by the native ATENA graphical environment and therefore the necessary commands must be entered manually or by using the ATENA GID interface GID see the Internet address http gid cimne upc es is a general purpose finite element pre and post processor that can be used for data preparation for ATENA See the README TXT file in the ATENA installation for the instr
42. uctions how to install the ATENA interface to GID In order to activate the creep analysis option an appropriate problem type must be selected Data Problem type AtenaV4 Static 2 1 Example of a static analysis with reinforcement In this example we demonstrate the usage of GiD for data generation of a simple structure The structure is a reinforced concrete L shaped cantilever It has fixed supports on one end and is loaded by vertical force near the free end See Figure 7 The first beam adjacent to the fixed end is subjected to a simultaneous action of bending and torsion while the second beam is only under bending A complex three dimensional behaviour can be well analysed by ATENA and for this purpose the input data can be prepared in GiD 2 1 1 Reinforcement modelling The longitudinal reinforcement is by bars 4828 that are located long the edges and by stirrups 12 with spacing 100mm in the first beam section A and with spacing 200mm in the second beam section B 11 Since there are different possibilities to model reinforced concrete we make first a decision about the modelling approach Concrete shall be modelled by 3D brick elements For this we chose the hexahedra elements The longitudinal reinforcement shall be modelled by discrete bars The stirrups shall be modelled as a smeared reinforcement within the reinforced concrete composite material This is a simplified method by which we avoid an input of detail geometry
43. ult behavior un assign all reinforcement node and element identification and then assign it again manually These two conditions should be manually assigned to all reinforcement line entities if error messages about reinforcement identification appear during mesh generation or during the generation of the ATENA input file Conditions Renforcement Modes Identification Displacement for Line eight For Heinf Line Temperature for Heinf Line Initial Strain for Heinf Line Initial Stress for Heinf Line Spring for Line Monitor for Line Fixed Contact for Line Reinforcement Hodes Identification Reinforcement Elems Identification Prior to that the automatic reinforcement identification check box should be deselected and all reinforcement identif Conditions unassigned Entities Unagsign Figure 27 Manual identification of reinforcement node 24 2 1 6 Meshing In the preceding description the geometry was defined and all properties material supports loading were assigned to geometry Now we shall generate a finite element mesh For this we must set up appropriate parameters in the menu Meshing Meshing v Normal Quadratic Quadratic Quadratic elements Assign unstuck sizes Structured Mesh criteria Element type Boundaries r or F F Bs Draw sizes k Reset mesh data Cancel mesh Generate Ctrl g Mesh view Ctrl m Mesh quality Edit mesh d Figure 28 Meshing menu 2 1 6 1 Mesh definiti
44. we define parameters of concrete component This can be done by selecting the tab Concrete Component 0 and modifying its parameters There are several choices available for the basic material It is recommended to select the material CC3DNonLinCementitious2 which is identical to the same material from the group Concrete The dialog window is extended to allow additional reinforcement components The buttons alela allow n adding new and deleting of materials When adding a new material with the button the default material is first copied then re named and edited The stirrups are modelled by smeared reinforcement as Component 1 of the composite material The first 5 parameters describe the initial elastic modulus reinforcing ratio and direction The reinforcing ratio of smeared reinforcement is calculated as p 4 A4 where A A are the section areas of bars and concrete respectively in the considered volume This ratio is different in each part of cantilever due to different stirrup spacing The direction of the smeared reinforcement is defined as a unit vector The constitutive law of the reinforcement is defined as multi linear by a sequence of points stress strain pairs The first point is defined by yield strength and elastic modulus This gives a bi linear elastic plastic law with unlimited ductility A general multi linear function can be defined by additional points Maximum 4 additional points can by given Up to
Download Pdf Manuals
Related Search