Home

User Manual - PUC-Rio

1. Chapter 3 Using ViDa Windows 8 04 13 Vid VV JOW Curves 52 Chapter 5 Advanced Issues Troubleshooting Database Information Input File Formats References CHAPTER 1 Welcome Welcome to ViDa the Fatigue Damage Calculator Fatigue and Fracture Mechanics calculations can be a very laborious task without a powerful software like ViDa mainly when we need to calculate the accumulated damage or the remaining life of a structure or equipment which work under complex loading In these cases all we really wish is just specify the material the applied stresses or strains and the appropriate stress concentration factor and let the computer do fast and accurately the dog work However most powerful computational tools are written by software oriented people their terminology is normally so strange not to mention how non intuitive most of the user interfaces are that you first have to learn how they internally work before being able to reliably perform even the most simple calculation But ViDa is different It has been developed by fatigue engineers to satisfy our design needs Having a basic fatigue training anyone can learn how to use its basic features in a glance Take the one minute challenge oee how fast you can make a full calculation of fatigue damage with ViDa Contents ViDa Main Features V
2. 00 Type of Loading Tension Effective Diameter 1 mm Su 441 MPa Operating Temperature 24 2 Cancel Calculation Title Title of the calculation that is about to be performed This is an optional field useful to identify and compare results from different calculations in the Calculation Logbook Window Sigmaf Elastic coefficient from Coffin Manson s equation de 2 Sigmaf E 2N b epsilonf 2N c Epsilonf b Plastic coefficient from Coffin Manson s equation de 2 Sigmaf E 2N b epsilonf 2N c Elastic exponent from Coffin Manson s equation de 2 Sigmaf E 2N b epsilonf 2N c 51 Plastic exponent from Coffin Manson s equation de 2 Sigmaf E 2N b epsilonf 2N c Calculate b c Button For Steels or Alumina Command Calculates the values of the parameters b c Sigmaf and epsilonf of the eN curve de 2 Sigmaf E 2N b epsilonf 2N c by loading them from the Materials Database and also correcting the elastic exponent b using the value of Sf ka kb kc kd ke Sf the same approach used in the SN Curve Calculate b c Button Materials Database Values Command Loads the values of the parameters b c Sigmaf epsilon of the curve de 2 Sigmaf E 2N b repsilonf 2N c from the Materials Database directly into the current window Calculate b c Button Experimental Points Command Loads the values of the parameters b c Si
3. i Automatic calculates b and c from the pair of points N S 1000cycles 0 9 Su and 1 000 000cycles Sf ka kb kc kd ke Sf for steels for alumina the 1 000 000 cycles is switched to 500 000 000 For steels an elbow is placed in the SN curve at N 1 000 000 39 ii b Sf Nf determines the SN curve using the point N S Nf Sf ka kb kc kd ke Sf and the exponent b iii b c Nf the SN curve is determined from the user supplied values of b c and the elbow location Nf Note that only in this option the Calculate b c Button is enabled Exponent of the SN Curve N S b c Coefficient of the SN Curve N S b c Nf Location of the elbow in the SN curve there is no fatigue damage for N Nf Calculate b c Button For Steels or Alumina Command Goes to the Calculate b and c for SN Window where the user can calculate the parameters b and c of the SN curve N S bzc Calculate b c Button Materials Database Values Command Loads the values of the parameters b and c of the SN curve N S bzc from the Materials Database directly into the current window Calculate b c Button Experimental Points Command Loads the values of the parameters b and c of the SN curve N S bzc from the Experimental Points Window directly into the current window Consider SN Curve Elbow Option Option to consider the elbow in the SN curve which defines no fatigue damage for stresses smaller than Sf ka kb kc kd ke Sf or number of cyc
4. KIc 5y 2 mm 8 Descending Ascending Material 400 foo fono fono fono fono fono fono X Cancel Type of material to be searched steels alumina etc Property Choose here the properties that you want to set ranges in your query Range Set the minimum and maximum value of the corresponding material property to be used in your query Order by Choose here the properties that you want to use to sort the results from your query Descending Ascending Choose the sorting order descending or ascending of the results from your query OK Button Evaluates your query and show the results in the Open Material window Cancel Button Cancels your query and returns to the Material window 34 Browse Material Window Lets the user browse all materials from the database showing all their properties You can rearrange the columns by dragging the column title with the mouse and dropping it over the desired position ViDa automatically sorts the table by the first column so if you want to order the materials e g by their Su just drag and drop it on the first column You can also resize the columns and all your layout changes are saved So just customize your table start browsing and double click on the material you want to load Browse Maternal Local vida mdb Mame Type E Su 5p 54 Ele Eth Sel b5n a 1 15 5AE 121 BHn
5. User Manual Information in this document is subject to change without notice No part of this document may be reproduced or transmitted in any form or by any means electronic or mechanical for any purpose without the express permission of ViDa Inc Copyright 1996 2002 ViDa Inc All rights reserved ViDa is a registered trademark of ViDa Inc Windows is a registered trademark of Microsoft Corporation This software is provided as is and any expressed or implied warranties including but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed In no event shall the author or his contributors be liable for any direct indirect incidental special exemplary or consequential damages including but not limited to procurement of substitute goods or services loss of use data or profits or business interruption however caused and on any theory of liability whether in contract strict liability or tort including negligence or otherwise arising in any way out of the use of this software even if advised of the possibility of such damage Any liability of ViDa Inc will be limited exclusively to product replacement or refund Contents Ghapt rZ Installing TONY mice n mom R Q VIDA EID c sie jiebub m
6. 00 1015 5 126 BHn 1015 SAE 80 BHn a 10187AI51 106 BHn 1018 AI51 118 BHn 1018 AI51 209 BHn 1020 AI51 105 109 BHn 1020 AI51 108 1020 SAE 108 BHn 1020 5AE 111 BHn 1020 5AE 131 BHn 1020 SAE 143 1020 SAE Default 1022 5 137 BHn 1022 5AE 143 BHn 1022 SAE 149 1025 AISI a 1025 AISI b 1030 AISI a 1030 AISI b 1030 5AE 126 1030 5AE 149 BHn 1030 SAE 179 1030 SAE 495 BHn 1035 AISI Hot rolled 1035 AISI QT a 1035 AISI QT b 479 Found List of all materials in the database or the ones that matched a query from the Find Material window Just click on the desired material to load the data Found Total number of materials found in the materials database or the ones that matched a query Cancel Button Cancels the material selection and returns to the Material window 33 Find Material Window Lets the user search for materials by their type steels alumina etc or by any property ranges e g materials with Su between 600 and 800 MPa or combinations of them You can also sort the matching materials by any property The results of your query are shown in the Open Material window Find Material Local vida mdb Maternal Aluminum Field Contains Property Su 200 s s ee Order by
7. 32 L Pi d 3 2 3 16 R Pi d 3 2 5 79 Options Window Window with ViDa general options In order to make the changes effective press the Apply or the OK buttons To cancel the alterations press Cancel This window has 4 tabs Editor Tab Options Database File Locations Loading Graph Loading Histogram Graph X Hysteresis Loops Graph Number Format 0 Window Open Rainflow results in New Window X Open Rainflow of Calculated Strains in New Window X Show Tips at Startup Show Loading Graph Option Lets ViDa show a Peak Valley graph of the Loading History on each Loading Window This option is useful to visualize the loading history but it may slow down ViDa if the history is too long Show Loading Histogram Graph Option Lets ViDa show a 3D bar chart of loaded bidimensional histograms Bidimensional histograms are loaded by opening a CSV csv or Excel xls file and turning on both the Histogram and the Mean Interval options Show Hysteresis Loops Graph Option Lets ViDa show the Hysteresis Loops plot for eN calculations Note that even if this option is turned off the Loops are still calculated but not plotted if you chose the Calculate Hysteresis Loops option on the eN Method Window Number Format Formatting mask to define the number of significant digits of all calculation results Open Rainflow Results in New Window Option ViDa creates a new Loading Window whe
8. 5 1 01 b c Eb To check information on the available commands please refer to the correspondent extended window 1 00000 0 10000 0 01000 i 0 00100 0 00010 0 00001 Cancel 55 Crack Growth da dN Extended Window Calculates unidimensional crack growth using the da dN Method and the loading history from the Main Window The user can input specimen characteristics such as its total width and crack initial size alter the material Paris or Elber law constants or include a new da dN or stress intensity factor equation which can be stored in the da dN or KI Equations Database input crack growth retard effects choose to use the RMS approach in the calculation and many other options Some of the default data in this window comes from the Materials database and the rest is maintained from your last calculation A simplified Crack Growth da dN window recommended for beginners is also available by using the Tools Options command in the Main Window and choosing the Simplified option in the Modeling tab prior to calculating the crack growth After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations da dN Curve Tab Calculation title Curve 7 00E 00 MPaVm 30E 02 Pars amp 1477E 07 m 2 DUE 00 Paris 5 33 07 E X Elber m 200E Elber Walker ParisZ 1 R p
9. Calculate Elber Button Materials Database Values Command Loads the values of the A and m coefficients of the Elber da dN equation da dN A deltaK deltaKth m from the Materials Database directly into the current window Calculate Elber Button Fitted from Experimental Points Command Loads the values of the A and m coefficients of the Elber da dN equation da dN A deltaK deltaKth m from the Experimental Points tab in the Materials Database directly into the current window Walker Option Option that let the user choose the Walker equation da dN A deltaK m 1 R p among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer Modified Walker Option Option that let the user choose the Modified Walker equation da dN A deltaK deltaKth m 1 R p among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer p pWa Exponent p from the Walker da dN A deltaK m 1 R p and Modified Walker da dN A deltaK deltaKth m 1 R p equations The default value of p is loaded from the Materials Database but it can be changed by the user Other Equation Option Option that let the user choose the da dN equation shown in the da dN Formula f
10. Calculate Life eN Extended Window Calculates the damage and remaining life using the eN Method recommended in the presence of plastic deformations at the critical point normally a notch root and the loading history from the Main Window The user can input specimen characteristics such as surface finish or equivalent diameter to determine the values of ka kb kc kd and ke to alter the elastic component of the eN curve alter the material eN curve equation calculate and input stress concentration factors choose to or not to calculate by following and plotting the hysteresis loops and many other options oome of the default data in this window comes from the Materials database and the rest is maintained from your last calculation A simplified Calculate Life eN window recommended for beginners is also available by using the Tools Options command in the Main Window and selecting Simplified in the Modeling tab prior to calculating life After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations eN Curve Tab Calculation title eH Curve Hysteresis Loops eH Curve Gi 8 96 02 Ei 4 10E 01 1 000000 b i300 0 100000 l DS inl 0 010000 J 5 10E 01 Ene di 0 001000 9 000100 0 000010 0 000001 Initial damage End of life damage Surface Finish Ground MPa 3 42E 01 O0E 00 9 23 01 O0E 00
11. IX SIBRAT COTEQ 96 pp 145 148 IBP amp ABCM 96 in Portuguese 5 Castro J T P amp Meggiolaro M A Residual Life Prediction of Cracked Structures Proceedings of COTEQ 97 pp 263 268 IBP and ABCM 97 in Portuguese 6 Meggiolaro M A amp Castro J T P Equationing of Fatigue Crack Growth Curves Proceedings of the II International Congress of Metallurgic and Material Technology ABM 97 in Portuguese 7 Meggiolaro M A amp Castro J T P Sequencing Effect Modeling in Fatigue Crack Growth Proceedings of the II International Congress of Metallurgic and Material Technology ABM 97 in Portuguese 8 Meggiolaro M A amp Castro J T P Sequencing Effects in Hysteresis Loop Prediction using the eN Method Proceedings of the II International Congress of Metallurgic and Material Technology ABM 97 in Portuguese 9 Meggiolaro M A amp Castro J T P ViDa 96 Visual Damagemeter to Automate Fatigue Design under Complex Loading submitted to RBCM 97 in Portuguese 10 Castro J T P amp Meggiolaro M A Remarks on the Automation of the eN Method for Fatigue Design under Complex Loading submitted to RBCM in Portuguese 11 Castro J T P amp Meggiolaro M A A Note on the Modeling of the Fatigue Crack Growth Curve submitted to RBCM in Portuguese 12 Castro J T P amp Meggiolaro M A A Note on the Automation of Fatigue Crack Propagation Reckoning under Complex Loading sub
12. In addition to typing the loading history with ViDa you can import files from other software It is possible to load comma separated value files e g generated from the Instron s Wavemaker software previously saved Alternate Mean or Peak Valley files or even experimentally generated files by the Kyowa RHS 500A histogrammer 1 On the Main Window choose the File Open command A standard load file window will appear 2 Click on the complex alt file and press OK Done The Datasheet is now loaded with Alternate and Mean components of your loading history These values represent stresses since the Table Option is set to Stress refer to the Tools Options command to define if these stress values are in MPa or ksi Now you can proceed to calculate life in the same way you did on the previous example Note also that you can view these Alternate Mean components as a sequence of Peaks and Valleys by clicking on Peak Valley in the Sequencing Option You can also add or delete rows by using the Edit menu Refer to the Edit menu for more information on data handling in the Loading Window Changing the Material ViDa has a complete Materials Database with stress strain curves SN eN and da dN data and many other properties of over 1500 materials This database can be expanded by the user with no storage limits and all the materials can be searched by user defined criteria e g searching for Alumina with Su between 400 and 500 MPa and sorting
13. Kt in the mean components of the loading history and iii to plot the results for the Soderberg curve calculations 13 Choose if you want to consider Residual Stresses in the SN calculation In this case you ll have to enter the Initial Residual Stress The program needs to draw hysteresis loops in order to consider residual stresses accurately so you can also specify i the range of hysteresis loops you want to plot ii the accuracy of the calculations and plotting resolution and iii which Strain concentration theory is to be used when stress concentration factors are present Note that in order to consider residual stresses effects ViDa changes from the SN to the eN method every time the local at the notch root stresses reach the cyclic yield strength e g due to an overload calculates the appropriate elastoplastic hysteresis loop by the eN method and goes back to the SN method carrying on the damage and the residual stress caused by the elastoplastic event The residual stress is added to the subsequent loads and its effects are quantified by the SaSm rules The main benefit of this technique is to decrease the computational effort as compared to the eN method 14 Enter the values of the Stress Concentration Factor Kt and of the Notch Sensitivity q These values can also be calculated using the Calculate Kt button Typical which goes to the Calculate Typical Stress Concentration Factor window and calculates both Kt and q gi
14. Mod walker Elber 1 R p deliak MIP aim 00 01 Forman m4 S A AK AK a 1 Ry EN Fit X Cancel 01 00E 00 QUE 01 2 DOE OD OE 00 OUE 01 aie aie at E RD VD T oUm x x Tem 3 BOE 00 Calculation Title Title of the calculation that is about to be performed This is an optional field useful to identify and compare results from different calculations in the Calculation Logbook Window deltaKth dKth Klc Threshold Stress Intensity Factor of the material value of deltaK below which the crack does not propagate The default value of deltaKth is loaded from the Materials Database but it can be changed by the user be careful with the Elber da dN equation since it s very sensitive to deltaKth Critical Rupture Stress Intensity Factor of the material The default value of Klc is loaded from the Materials Database but it can be changed by the user 56 Paris Option Option that let the user choose the Paris equation da dN A deltaK m among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer A APa Coefficient A from the Paris equation da dN A deltaK m The default value of A is loaded from the Materials Database but it can be changed by the user m mPa Exponent m f
15. Other keyboard commands are Enter move down one cell Arrows move along cells Ctrl Arrows jumps to the beginning or end of table Shift Arrows selects group of cells for copying etc Ctrl dragging the mouse copies current cell value to all your selection Shift Delete deletes the selected rows Shift Ins inserts rows Table Option Option that defines if the values from the Loading Window represent stresses in MPa or ksi or strains in microstrains Sequencing Option Defines the data format from the Loading Window either alternate mean components or peak valley counts The loadings in the Loading Window are automatically converted from one to the other format Loading Time Duration in seconds of ALL events in the Loading Window It is used in the residual life estimate calculation Filter Amplitude filter that can be automatically used when calculating Rainflow or Sequential Rainflow of a Peak Valley history Note that you need to enter its value prior to the Rainflow calculation You can also Filter the history by using the Edit Filter command Set the Filter to zero in order not to filter the loading datasheet Loading Graph Plots the loading history from the datasheet To redraw it right click with the mouse and select Redraw You can also paste almost any previous data copied in Windows For instance you can select a group of cells in Excel copy them right click on this graph and select Paste You
16. ViDa calculates crack growth using any da dN equation specified by the user recognizing retardation and even crack arrest effects 1 From the Main Window choose the Life Crack Growth command and the Crack Growth da dN window will appear 2 Type the initial crack size and the specimen width 3 Choose which da dN equations you want to use in the calculations and press the OK button The total and average crack growth are almost instantly displayed on the 2 bottom rows of the Loading Window Bidimensional Crack Growth Surface cracks grow bidimensionally i e both sideways and in depth Certainly we cannot rely in pure unidimensional crack growth calculations ViDa handles these bidimensional cracks and calculates crack growth in both directions considering the changes in crack shape and retardation and crack arrest effects 1 In the Main Window make sure that the Extended Modeling option is chosen using the Tools Options command This option is required to let ViDa calculate bidimensional crack growth 2 From the Main Window choose the Life Bidimensional Crack Growth command and the Bidimensional Crack Growth da dN and dc dN window will appear 3 Choose the type of the crack in your specimen among Semi Elliptic Corner Internal crack or even surface cracks on a cylinder wall under pressure 4 Type the initial crack size dimensions a and c and the specimen width and its other dimensions 5 Choose which da dN equations
17. curve graph plotting the experimental points and or the fitted curves from the calculated properties data Note that the graph is only updated after you save the data using the File Save command da dN Graph Log da dN x Log deltaK curve graph plotting the experimental points and or the fitted curves from the calculated properties data Note that the graph is only updated after you save the data using the File Save command Hardening Graph Stress strain curve graph plotting the experimental points and or the fitted curves from the calculated properties data Note that the graph is only updated after you save the data using the File Save command 30 Calculated Properties Data Properties calculated from the curve fittings from the experimental points Fit SN Button Fits the SN experimental data points using a least squares method for a Wohler equation N S b c The b and c constants are calculated and the fitted curve is plotted on the SN graph To use these calculated b and c in life calculations you need to copy them to their respective field in the Fatigue and Fracture tab and use File Save Fit eN Button Fits the eN experimental data points using a least squares method for a Coffin Manson equation The 4 eN curve constants are calculated and the fitted curve is plotted on the eN graph the Young modulus E comes from the monotonic data Note that since there are 4 constants in the eN curve instead of only 2 you need data
18. 11 00 01 5 50E 00 Calculation Title Title of the calculation that is about to be performed This is an optional field useful to identify and compare results from different calculations in the Calculation Logbook Window deltaKth dKth Threshold Stress Intensity Factor of the material value of deltaK below which the crack does not propagate The default value of deltaKth is loaded from the Materials Database but it can be changed by the user be careful with the Elber da dN equation since it s very sensitive to deltaKth 66 Klc Critical Rupture Stress Intensity Factor of the material The default value of Klc is loaded from the Materials Database but it can be changed by the user Elber Option Option that let the user choose the Elber equation da dN A deltaK deltaKth m among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer A AEI Coefficient A from the Elber equation da dN A deltaK deltaKth m The default value of A is loaded from the Materials Database but it can be changed by the user m Exponent m from the Elber equation da dN A deltaK deltaKth m The default value of m is loaded from the Materials Database but it can be changed by the user Calculate A m Elber Button Materials Database Values Command Loads the values o
19. 126 207 464 341 195 57 33 2 32E 02 1 15E 0 E H X Cancel Teed 4 4 4 4 eed eed 7 0 ed ed ee 77 7l Materials Table Shows all available materials in the database You can customize the table layout by dragging and dropping the columns as well as resizing them ViDa automatically sorts the table by its first column and all your layout changes are automatically saved To load a material to the Material window just double click on its name or select it and press the OK button Help Button Shows more information on this window Refresh Button Updates the table to reflect your most recent changes in the Material database You only need to use this button if you have made changes to the Material database in this session of ViDa Default Layout Sets the column order and column widths of all properties to the default value used in ViDa You can use this button if you made too many changes in the table layout and want to revert it back Group Cells Changes the display mode so to group equal values into one larger cell OK Button Loads the selected material and returns to the Material window Alternatively you can just double click on the Materials table on the name of the material you want to load Cancel Button Cancels the material selection and returns to the Material window 35 Calculate b and c for SN Window Calculates the b and c constants of the SN curve N S b c using the us
20. AEI mEI To REN Symbolic Option Sets the Smart Calculator as a Symbolic calculator with a Formula field where the user can enter any symbolic equation By using the Calculate SI or ksi buttons the Formula is evaluated and the result is shown in the X field ce AEI mEI To 78 Material Tab Tab containing buttons associated with the properties of the current material Click on each button to show its numerical value for the Numeric option or to write the property name on the Formula field for the Symbolic option User and Values Tabs Variables Table Table containing variables that can be set by the user To set a variable just click on it and type its new value If these variables are present in the Formula field then their values are used in the calculations Formula Equation that will be computed in the Smart Calculator This equation may include any variable from the Variables Table any material property or even mathematical functions click on the Equation Interpreter Help Button for more information X Result Result of the calculation using the equation in the Formula field material properties and Variables Table values Equation Interpreter Help Button Shows a help window with all the variables material properties and mathematical functions that can be used in the Formula field of the Smart Calculator C Clear Button Clears the Formula field for the Symbolic o
21. Condition HR Plate k z 38E 02 MPa Cost Range p fp t kg 80E 01 T operating or k 7 72E 02 MPa a T melting Thermal Exp ii5 9 5 pec weight 76 5 kN m Charpy 1 3DE 02 J Poisson 0 232 roung 203 GPa BHn 108 Su 441 62 Sigma MPa 04 OF 0 7 0 8 e mim Name Name and comments to tell apart similar materials each material name comment must be unique Material Material type steel aluminum etc Code Sequencing code for the material automatically administered by ViDa Source Reference source for this material data 26 Composition Chemical composition of the material Condition Consists of 2 fields i the mechanical treatment applied to the material and ii the grain direction resulting from the rolling direction L longitudinal T transversal W width Cost Range Minimum and maximum market prices for this material T Operating Operating Temperature in which the properties were measured T Melting Melting Temperature of the material Thermal Expansion Thermal Expansion Coefficient of the material Specific Weight Specific weight of the material Charpy Amount of energy absorbed by the Charpy specimen Poisson Poisson coefficient E Young Young modulus be careful with the units BHn Brinnell Hardness Su Ultimate Strength Sy Yielding Strength Sy Cyclical Yielding Strength used in hysteresis loops Si
22. Define R Kmin Kmax Command Plots the da dN equation shown the da dN Formula field for different values of R Kmin Kmax The user is asked to input the range of R values to be considered and the number of curves to be plotted This command is useful to visualize the influence of R and Kmin and Kmax in the da dN equations that include these variables 22 Copy Command Copies ALL points from the graph to the Clipboard You can then paste it to another graph paste into any other application or even paste it directly to an Excel worksheet If you paste it to an imaging software like Paint you ll be get the picture image of the graph Paste Command Pastes the data from the Clipboard into the current graph You can paste a group of cells copied from any ViDa Loading window or from an Excel worksheet If more than 1 column was copied then the graph pairs consecutive columns to plot one against another So if you paste 5 columns into the graph columns 1 and 2 will determine a set of points coordinates X and Y respectively 3 and 4 will form another and column 5 will be ignored since it can t be paired If you paste only 1 column its values are plotted in the Y axis and the X axis will contain the row number of each point Redraw Command Redraws the graph updating any changes from the user Tip for the da dN graph in the Crack Growth window you can easily tune in the coefficients of the da dN Formula by interactively editing t
23. To expand or shrink the graph just double click on it Critical Stress Intensity Factor fracture toughness deltaKth dKth Threshold Stress Intensity Factor if deltaK deltaKth the crack does not propagate A Paris Coefficient A used in Paris law da dN A deltaK m m Paris Exponent m used in Paris law da dN A deltaK m A Elber Coefficient A used in Elber law da dN A deltaK deltaKth m m Elber Exponent m used in Elber law da dN A deltaK deltaKth m p Walker Exponent p used in Walker law da dN A deltaK m 1 R p and also in the Modified Walker law da dN A deltaK deltaKth m 1 R p CTOD Value of the critical CTOD Crack Tip Opening Displacement Calculate Paris Button Experimental Points Command Loads the values of the A and m coefficients of the Paris da dN equation da dN A deltaK m from the Experimental Points tab in the Materials Database directly into the current window Calculate Paris Button From eN Curve Command Calculates the constants of the Paris law da dN A dK m from the eN Curve parameters by using the assumption that crack growth is caused by the successive breaking of tiny eN specimens see the Textbook Fatigue Design under Complex Loading After the calculation the estimated A and m values are color coded in red Calculate Paris Button Rolfe Barson Command Sets the constants of the Paris law da dN A dK m depending on the microstructure of the m
24. View menu Material List Name of the material that will be used in the calculations except for welded structures which depend only on the IIW weld class To change the material use the Data Material command or just click on the list box to change it Status Bar Shows a Progress bar on how long it takes to perform a calculation To stop a calculation in progress just press ESC 14 Loading Window One of the windows from the Main Window containing the loadings for each event which can be either typed or loaded from a file The first column shows the number of the event each event can consist of many cycles When the Alternate Mean option is chosen at the Sequencing Option the next 3 columns show the alternate and mean components of the loading and the number of 75 cycles that it is applied If the Peak Valley option is chosen at the Sequencing Option then these 3 columns are replaced by a single one containing the peaks and valleys of the loading After the calculations the table also shows the damage or crack growth associated with each model The 2 bottom rows contain the total damage and the residual life of the specimen considering that the loading history continues to be applied on the specimen at the same rate defined in Loading Time For crack growth calculations the 2 bottom rows show instead the average da dN and the total crack growth In order to edit the datasheet just click on the desired cell and start typing
25. a7w 21 Z a w rs aw 0 2 0 Bcr s 1 12 a w 43 a w 2 0 6697 a7w 3 aoe f 3 x w1 941 1 a w 780 rack Splitting forces a wi x 22 1 0 25 1 a w 27wZ rew 7 H tuuc a aaa a 1 a w 1 5 2 11 3 5544 a w Circ disc central crack 1 m 5 a7 2 w 1140 Compressive forces colinear to 1 5873 a 2 w 2 1 crack 2 2 2 b l a 2 w 3 1 0 5 a7 2 w 1090 2 1 6873 a 27w 2 crack face stress 2 2 7 2 B7 17 a 27w 3 Circ disc central crack Quadratic 0 5 0 25 a 2 w 1100 stress distribution 5igmal7 x a 2 044 17 a 2 w 2 2a 2w 74 1 1091 a 27w 3 1110 Circ disc single edge crack w 0_5457 asa 2 0 4057 a w 3 1 Mormal crack face stress a w 15 1 a w 1 5 Name of the equation each equation name must be unique Code Sequencing code for the equations automatically administered by ViDa Source Reference source for this equation Formula Contains the equation itself Click on the Equation Interpreter Help button to get more information about the equations syntax Equation Interpreter Help Button Shows just for reference a window with the equations syntax and all the material properties that can be literally used Memo Additional information about the equation Figure Name of the graphic file containing the selected equation located in the directory 2002 Delete Button
26. and c The corner crack is assumed to be a quart ellipsis the surface crack a semi ellipsis and the internal crack a full ellipsis The cracks can change the a c ratio during their propagation but remain elliptical The user can input specimen dimensions and 2D crack characteristics such as its initial type and dimensions alter the material Paris or Elber law constants or include a new da dN equation which is stored in the da dN Equations Database input crack growth retard effects choose to use the RMS approach in the calculation define desired output graphs to be plotted after the calculation and many other options oome of the default data in this window comes from the Materials database and the rest is maintained from your last calculation This window is only available with the Extended Modeling option from the Options Window After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations da dN Curve Tab Calculation title da dM Curve AKa r00E 00 MPaMm Kic 1 30E 02 HMPat m A 4 7 7E U7 Paris i m 200E 00 Paris ix Eme 215 3347 Ez m 2 00E 00 Elber Walker Paris 1 R p Elber Mo QR 0 X Mod walker Elber 1 R p deltak MP aim p pa 00 01 nther 5 23E 06 5 DOE 00 11 00 02 2 17 00E 00 17 30E 02 3 00E 00 5 UE 02 3 00E 01 11 00 03 1 00 00
27. and the residual life of the specimen or the average da dN and the total crack growth for crack growth calculations for all the calculations performed by ViDa in the current session Just double click on the title cells to edit its contents Double click on the internal cells to see the Memo of each calculation the calculation parameters used in each case Print Memo Option to print the Memo column of the table To print the table use the File Print command from the main menu SN Tab Tab containing the Table with the SN Method life calculation results IIW ECCS Tab Tab containing the Table with the Welded Structures life calculation results eN Tab Tab containing the Table with the eN Method life calculation results da dN Tab Tab containing the Table with the unidimensional crack growth calculation results da dN 2D Tab Tab containing the Table with the bidimensional crack growth calculation results 12 Calculate Equivalent Stress Window Tridimensional Peaks and Valleys Tab Calculates equivalent stresses for a list of 3D stresses with normal and shear components There are 4 ways to calculate these equivalent stresses i Mises criterion ii Tresca criterion iii Maximum Stress considering changes in sign for alternating stresses and iv Maximum Absolute Stress neglecting changes in sign for the stresses The user can also include individual stress concentration factors for each stress component prior to th
28. button The damage and residual life will be calculated and shown in the Loading Window Note that the residual life in days depends on the Loading Time value from the Loading Window 89 How do Calculate Damage using the eN Method To calculate the fatigue damage and the remaining crack initiation life of a piece which critical point works under elastoplastic stresses you should use the eN method This method can also be used for elastic stresses but its computational effort is higher than the one required by the SN method Below there is a complete list of all steps you might need to go through to perform this calculation Note that some of these steps can be skipped in some cases and also some of the options are not available in the Simplified Modeling option the symbol will denote options only available in the Extended Modeling option 1 Load a Loading History or type it in the Loading Window Fill out the Loading Time field with the duration in seconds of ALL the loading history in order to calculate the estimated residual life in days of the piece 2 If the loading is a sequential history you might want first to Check or Filter it If your loading history consists of deformation Peak Valleys it is recommended to use a rainflow counter Make sure that the history in the Loading Window is expressed as a Peak Valley sequence by clicking on Peak Valley in the Sequencing Option enter a value for the amplitude Filter opti
29. by a custom model For calculations using the SN method some theories suggest that the stress concentration factor Kt should only be applied to the alternate stress and ignored for the mean To consider these theories clear the Use Kt in Smean option on the SN method window For compressive mean stresses the SaSm damage curve is modeled in ViDa as a straight line with a slope ranging from 0 flat to 100 of the Goodman curve slope The beneficial influence of compressive mean stresses which can extend life can then be valorized by increasing this percentage on the SN method window To view the SaSm diagram for a user defined life in number of cycles right click on it with the mouse on the SN method window and choose Define Life for SaSm The default plotting life is 1E6 cycles but it can be drawn for any other value Note that this command doesn t influence at all the life calculation To define the total damage value that characterizes failure of the piece type the desired value on the End of Life at Damage field on the SN IIW or eN method window The Palmgreen Miner rule suggests a total damage value of 1 but you can enter any other value To calculate Stress Concentration Factors Kt on the SN or eN method window click either on the Calculate Typical Kt button which lets you calculate both Kt and q given a desired geometry and Su or on the Calculate Database Kt button which lets you calculate Kt from previous entries in th
30. can be from your hard disk after the ViDa installation e To access the Textbook Fatigue Design under Complex Loading from the ViDa program click Multimedia from the Help menu and choose Slide Show 11 Registering ViDa ViDa must be registered to become fully functional If not registered ViDa expires after 21 days To register ViDa Once you have installed ViDa click Register from the Help menu Send us by fax or e mail the Software Code shown on the screen of each computer you ve installed ViDa and we ll send you the Liberation Key s In the Register window type in the Liberation Key your Name and click Register ViDa becomes fully functional after registering Pa Register YiDa 2001 Read the REGISTER TXT file for more information on registering 12 CHAPTER 3 Using ViDa Windows It is fast and easy to make calculations of fatigue damage with ViDa ViDa has been developed by fatigue engineers to satisfy our design needs Having a basic fatigue training anyone can learn how to use its basic features in a glance Contents Main Window Handling all ViDa Graphs Standard Open Save File Window Open CSV Excel File Window Material Window General Tab Fatigue and Fracture Tab Experimental Data Tab Open Material window Find Material Window Browse Material Window Calculate b and c for SN Window Equations Database Window Calculate Life SN Extended Window Calculate Life SN Simplified
31. damage done to the specimen 0 being no damage and 1 being failure and its remaining life in days considering that the same rate of loading will be applied Are you ready Check your clock off we go 1 In the Main Window click on the cell right below Alternate in the Loading Window Type 100 Press the right arrow key gt and type 100 below the Mean heading the load is pulsating therefore it has equal alternate and mean components Now press the right arrow key gt and type 200000 meaning 200000 75 cycles equal to 100000 cycles We are on the first of three steps 2 Click on the box next to Loading Time and type 10000 which is the duration in seconds of your loading history Also check if the Table option above the Loading Window is set for Stress MPa 3 Select Life SN Method from the menu The SN Method window will appear Check if the stress concentration factor Kt on the bottom of the window is set to 1 Click on the OK Button You re done The damage and remaining life time are almost instantly displayed on the 2 bottom rows of the Loading Window as predicted by the Soderberg the Goodman the Gerber and even by a custom model How long did that take you Even if you didn t break the one minute barrier first time around consider this you have just completed a full SN Method fatigue life calculation all in about a minute Now that wasn t hard was it Loading a History
32. elastic component of the eN curve The graph is updated after changes in its parameters only when the Graph Redraw command is used To expand or shrink the graph just double click on it Hysteresis Loops Tab Hysteresis Loops Hardening 1 80 01 4 True Hardening Curves kK f2E 02 5lrain Concentration Linear Theory Ke Kt Neuber System Ke Ks Kt 2 Elastoplastic Nominal 5tress Hr E e Mer Mum l e mm Calculate Hysteresis Loops Loop Corrections highly recommended Rainflow of Calc Strains Amplitude Filter 0 Plot Cyclic 5 Curve over the Loops Define Loops to Plot Initial Final 00 Calculation Pts Plotting Pts n Hardening exponents of the cyclic curve using Ramberg Osgood equation k Hardening coefficient of the cyclic curve using Ramberg Osgood equation 53 Hardening Curve Shows the cyclic true hardening curve of the material Note the change in color marking on the graph the value of Sy To expand or shrink the graph just double click on it Strain Concentration Option Strain concentration theory used when considering stress concentration factors on the hysteresis loops Linear theory considers Ke Kt strain concentration Ke is equal to Kt while Neuber theory uses Ke Ks Kt 2 Elastoplastic Nominal Stress Solves the Neuber system considering that the nominal stress is elastoplastic This option gives more accurate results if
33. input stress concentration factors and some other options oome of the default data in this window comes from the Materials database and the rest is maintained from your last calculation Many more options are available in the extended Calculate Life SN window which is available by using the Tools Options command in the Main Window and choosing Extended in the Modeling tab prior to calculating life After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations Calculation title Automatic C b SENE 396 9 b c NI ia dn 349E 00 E pan 4 53E 27 A 235 294 un 191 042 1000 10000 100000 1 006 1 007 N Surface Finish Ground 1220 5 of Loading Tension 9 42E 01 1 00E 00 Effective Diameter n 9 23 01 rid 1 00 00 Operating Temperature 24 4 K 2 00E 00 E q 7 67E 01 q OK Cancel To check information on the available commands please refer to the correspondent extended window 43 Calculate Effective Diameter Window Calculates the effective diameter of different cross sectional profiles for bending This diameter is used in the Calculate Life window for SN or eN methods to calculate the size factor kb used to correct the fatigue endurance limit Click on the corresponding button and enter the profile dimensions to calc
34. inserted below the last selected row To assign a value to a group of cells of the Loading Datasheet select the cells to be set by dragging the mouse click Fill on the Edit menu and enter the desired numerical value Alternatively try dragging one cell with the mouse while pressing CTRL to copy its value to all your selection To multiply ALL the values of the Alternate and Mean or Peak Valley columns of the Loading Datasheet by a constant value click Multiply by Constant on the Edit menu and enter the value of this constant To convert the numerical values of ALL stresses on the Loading Datasheet from MPa to ksi or ksi to MPa click MPa ksi or ksi gt MPa on the Edit menu Note that this only changes the Loading Datasheet To choose English or SI units for the whole software select Options on the Tools menu and the Units tab To check the coherence to avoid two successive peaks or valleys of a Peak Valley history click Check Peak Valley on the Edit menu The incoherent events are automatically eliminated from the Loading Datasheet 100 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 To automatically convert the Loading Datasheet entries from Alternate Mean to Peak Valley components or vice versa click on the Peak Valley or Alternate Mean option above the Datasheet The loading time is the duration in seconds of ALL events in the Loading Datasheet Use it to e
35. integration step If the Simpson Integral option is on then the user may input a value for the integration step which is a percentage of the crack dimensions a and c If you chose the Simpson Integral option then you can skip step 18 18 Enter the Percentage value of the Increase in Va and Vc Criterion increase percentage of the square root of the crack size for which the Stress Intensity Factor 15 recalculated used to speed up the calculations Typical values are in the 0 1 1 0 range Click on the Increase in Va and Vc Criterion Help button for additional information 19 Choose to or not to use logarithmic interpolation to iterate within each step in the numerical integration only applicable for the Sequential calculations Since the value of da dN and dc dN vary within an integration step setting this option on makes the program iterate once for each integration step Slightly better accuracy is achieved with this option on 20 Choose which equations you want to use in the crack growth calculation among Elber law Modified Walker law and another da dN equation and press the OK Button The total crack growth in the a and c directions and average da dN and dc dN will be calculated for the chosen da dN equations and shown in the Loading Window 95 How Use the Materials Database In the Material window it is possible to manipulate the Materials database adding deleting changing or just selecting a specific
36. is possible to consider the loading history as a superposition of Normal and Bending stresses on some of the pieces of the Bidimensional Crack Growth window Use the Tension and Bending Factor fields to set the values from O to 1 by which the loadings are multiplied 105 Other Tips 94 95 96 97 98 99 100 101 102 103 104 105 106 You can calculate equivalent stresses or strains for a 3D stress history with normal and shear components each with its own stress concentration factor using Mises or Tresca criteria on the Equivalent Stress window Click Equivalent Stress on the Tools menu to enter it The resulting 1D components can then be used for life calculations When working with a 3D stress history that will be used in crack growth calculations choose Maximum Principal Stress on the Calculate menu This option is most appropriate for crack growth since cracks tend to grow perpendicular to the maximum tensile stress direction not being influenced by compressive stresses You can calculate equivalent stresses or strains for a list of strain triplets measured from a rectangular or delta Rosette on the Equivalent Stress window Click Equivalent Stress on the Tools menu to enter it The resulting 1D components can then be used for life calculations When working with strain triplets from a Rosette click Principal Direction on the Calculate menu to view the principal directions If these dir
37. is used to correct the elastic component of the eN curve Calculate d Effective Diameter Button Goes to the Calculate Effective Diameter Window where the user can calculate the effective diameter of various cross section profiles under bending This diameter is used to calculate the size factor kb used to correct the fatigue endurance limit Sf affecting the elastic component of the eN curve Su Ultimate strength of the current material used to automatically calculate the endurance limit modifying factor ka the endurance limit from the SN method is used to correct the elastic component of the eN curve The default value of Su is loaded from the Materials Database but it can be changed by the user Operating Temperature Specimen operating temperature used to automatically calculate the endurance limit modifying factor kd the endurance limit from the SN method is used to correct the elastic component of the eN curve Sf Uncorrected endurance limit of the material alternate stress below which there is no fatigue damage Note that the endurance limit is a concept normally used in the SN method but in ViDa it can also be used to correct the elastic component of the eN curve ka Surface finish factor that modifies the endurance limit a better surface finish increases the endurance limit Note that the endurance limit and its modifying factors are originally from the SN method but in ViDa they can also be used to correct the elast
38. loadings using the Table option You can also enter stress concentration factors for each component of the 3D tensor used in the equivalent history calculation 2 For Rosettes go to the Calculate Rosette Equivalent Stress window and type in the Peak Valley strain in microstrains loading histories for all 3 Rosette components A B and C in the Rosette Table You can also alter the Poisson coefficient and the Young modulus E of the current material and even define a direction on which you want to project the calculated stresses strains 3 You can also load a Peak Valley file into one or more of the columns of the Tridimensional or Rosette Tables selecting the desired column s and loading a pic file load a Tridimensional Peak Valley file file extension p3d or load a Rosette Peak Valley file file extension ros 4 Choose the desired equivalent stress or strain calculation from the Calculate button The result of the calculation is shown in the Equivalent Peak Valley table and in the Input Output graph 5 The resulting stresses or strains shown in the Equivalent Peak Valley table can be transferred to a new Loading Window of the Main Window using the Transfer button returning to the Main Window Done A new Loading Window has been created containing an equivalent Peak Valley history You can now calculate fatigue damage or crack growth using these loadings 98 How do Use the Smart Calculator ViDa has an alphanu
39. mouse cursor after 2 seconds 3 For 3D graphs you can rotate the angle of view by pressing the CTRL key while moving the mouse 4 f you right click with the mouse on any graph a pop up menu appears with some of these commands depending on which graph m Pop Up Menu Zom Log Log Thin Lines Engineering Define Life Define R Copy Paste Redraw Save Print Zoom Command Lets the user set the minimum and maximum values of the y axis of the graph or a range of points to be plotted After setting the Zoom a check mark is placed on the Pop Up menu To return the Zoom settings to the original values just click again on this command to uncheck it Log Log Command If this option is checked the graph is plotted in Log Log format Uncheck it to plot in Linear Linear format Thin Lines Command Toggles the line thickness of the Hysteresis Loops Elliptic Cracks graph between thick and thin Setting thin lines is especially useful when too many hysteresis loops are plotted in the same graph Engineering Command Plots the Engineering instead of True stress strain curves in the Hardening Curve Graph of the Material window If you uncheck this option the True stress strain curve is plotted instead Define Life for SaSm Graph Command Redraws the SaSm diagram of the SN Method window for a user defined life in number of cycles for reference purpose The default life for plotting the SaSm diagram is 1 000 000 cycles
40. p from Walker and Modified Walker laws prior to the calculations In general you don t need to change these values since they re automatically loaded from the Materials Database for the current material Note that the next time you call the Crack Growth da dN window these properties will be loaded again from the Materials database meaning that altering their values will only affect the current calculation You can also calculate or retrieve the values of A and m from either Paris or Elber laws from the Materials Database by using the Calculate A m Paris or Elber buttons Right click on the da dN curve graph and choose Redraw to see the changes in it 7 Choose other da dN equation that can be used in the crack growth calculation besides Paris Elber Walker and Modified Walker equations from a list of equation names loaded from the da dN equations database The chosen equation will be displayed in the Formula field Right click on the da dN curve graph and choose Redraw to see the changes in it 8 You can directly alter the formula for the chosen equation in the Formula field click the button for information on the available functions from the equation interpreter Note that the next time you call the Crack Growth da dN window this formula will be loaded again from the equations database meaning that directly altering the formula will only affect the current calculation In order to save an edited formula as a new equation
41. return without carrying this value Material Steel C Aluminum Cast Iron Titanium Copper Other ua y q em ETISIETIVI L 4 Su cr ari Hotch NEN 0 6 Hadius mm 2 4 7 67E 01 0 4 0 1 z 3 4 E X Notch Radius mm Cancel q Graph Shows the notch sensitivity values as a function of the Notch Radius and Su Su Ultimate strength of the material used to calculate q The default value is loaded from the Materials Database but it can be changed by the user Notch Radius Radius of the notch on the specimen used to calculate q Material Option Option of material type for calculating q Note that q doesn t depend on Su for Alumina Calculated value of the Notch Sensitivity for steels or alumina given the Notch Radius and Su OK Button Returns to the Calculate Life SN window carrying the Calculated q value Cancel Button Returns to the previous window without carrying the Calculated q value 48 Calculate Life of Welded Structures Window Calculates the damage and remaining life of welded structures using the IIW International Institute of Welding Method and the loading history from the Main Window The user can input the weld joint class which is the stress range in MPa that leads to a 2 000 000 cycle life to that specific weld type the exponent m from the IIW equation N cycles 2 000 000 weld class applied stress m the numbe
42. the nominal stress is higher than Sy but increases the computation time Calculate Hysteresis Loops Option Option to or not to calculate the hysteresis loops This option is a critical one in eN life calculations If the option is off then the calculations are made without calculating and constructing the hysteresis loops just directly applying the traditional eN equations which can result in significant and probably non conservative calculation errors Especially if you have a complex loading history then it is strongly recommended to set this option on in addition to the Loop Corrections Option in order to obtain an accurate result Loop Corrections Option Option to or not to correct the hysteresis loops using some experimentally proven criteria It is highly recommended to set this option on because uncorrected hysteresis loops taken directly from the hysteresis loops equations can lead to unrealistic and probably non conservative stress strain predictions see the Textbook Fatigue Design under Complex Loading for more information Plot Cyclic S e Curve over the Loops Option Option to or not to plot the stress strain cyclic curve together with the hysteresis loops just for visualization purposes This curve is useful to visually compare the corrected and uncorrected hysteresis loops set in the Loop Corrections Option Rainflow of Calculated Strains Option Option to rainflow count the calculated strains After the strains are calcu
43. the value of Kt for Notched Filleted Bars or Shafts of any dimensions Calculate Kt Button Stored Command Goes to the Smart Calculator window where the user can calculate the value of Kt using the equations from the Kt Equations Database or any other equation defined by the user OK Button Calculates damage by the eN Method using the Loading Window loadings the material properties and the chosen options and goes back to the Main Window Cancel Button Cancels the eN Method calculation and goes back to the Main Window 54 Calculate Life eN Simplified Window Calculates the damage and remaining life using the eN Method recommended in the presence of plastic deformations at the critical point normally a notch root and the loading history from the Main Window The user can alter the material eN curve equation and calculate and input stress concentration factors The default eN curve data in this window comes from the Materials database and the Kt value is maintained from your last calculation Many more options are available in the extended Calculate Life eN window using the Tools Options command in the Main Window and the Extended option in the Modeling tab prior to calculating life After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations Calculation title eH Curve Curve Gi 8 96 02 MPa Ei 4 1 01 b 1 20E 01 Ep uh
44. values of the material properties You can press the space bar on any value in order to toggle between black or red coding colors black for measured more reliable properties and red for estimated properties After entering the known properties you can use the Edit Estimate using Nominal Values command to estimate the remaining properties from Nominal Values and the known properties Finally click on the File Save As New command to create the new material Estimating properties you can estimate material properties from Nominal Values and the known properties Just click on the Edit Estimate using Nominal Values command to let ViDa estimate the missing properties the ones with null values If you want to clear the previously estimated properties the ones color coded in red you can use the Edit Clear Estimated Values command prior to the new estimation For more information on the estimates click on the Estimates Help button which shows just for reference a window with all the equations used to estimate properties from Nominal Values You can also interactively estimate the values of b and c from the SN curve or the values of A and m from the Paris law using the Calculate buttons Don t forget to use the File Save command to save the estimated properties and make them effective and available for further calculations Entering experimental data points to enter experimental data points which can be used to fit SN eN or da dN curves
45. with not only the number of reversions 2N and the strain variation de 2 but also with the corresponding stress variation dS 2 To use these calculated constants in life calculations you need to copy them to their respective field in the Fatigue and Fracture tab and use the File Save command Fit Paris Button Fits the da dN experimental data points using a least squares method for the Paris law da dN A deltaK m The A and m constants are calculated and the fitted curve is plotted on the da dN graph To use these calculated A and m in life calculations you need to copy them to their respective field in the Fatigue and Fracture tab and use File Save Fit Elber Button Fits the da dN experimental data points using a least squares method for the Elber law da dN deltaKth m The user then inputs the value of deltaKth that will be used in the curve fitting the default value is the one from the Material window The A and m constants are calculated and the fitted curve is plotted on the da dN graph To use these calculated A and m in life calculations you need to copy them to their respective field in the Fatigue and Fracture tab and use the File Save command Fit Monotonic Cyclic Button Fits the hardening experimental data points using a least squares method for a Ramberg Osgood equation To use these calculated n n k and k in life calculations you need to copy them to their respective field in the General t
46. you should use the Save As New button or go to the da dN Equations Database Window Right click on the da dN curve graph and choose Redraw to see the changes in it 9 Alter the values from the Variables Table in order to adjust the parameters of the chosen da dN equation Just click on the desired variable and enter its new value you can also load a previously saved Variables file var which contains all values from the Variables Table You can visually adjust the chosen da dN equation in order to be compatible with Paris and Elber equations by interactively altering 92 the variables values and right clicking on the da dN graph and choosing Redraw in order to see the changes in it You can also calculate the da dN value for a specific deltaK and R Kmin Kmax by clicking on the Calculate button 10 Enter the values of the specimen width w measured in the direction of the crack growth the initial crack size a and also a reference final crack size for which the calculations should stop in order to ignore this final value criterion just set the final value to zero 11 Choose a stress intensity factor KI equation that will be used in the crack growth calculation from a list of equation names loaded from the equations database Note that the Sigma V pi a term is already built in so the equations are actually the geometry factors beta 12 After choosing KI from the list the corresponding equation will be di
47. 00 z amp 00E 1 Cancel Initial Crack a Initial size of the crack length a Final Value a Size of the crack length a above which the calculation stops This is one of the criteria to stop the calculations and it can be used for instance to calculate the number of cycles that it takes to reach a certain crack size If you don t want to use this criterion just set it to a very high value Initial Crack c Initial size of the crack length c see the Crack Type Drawings Final Value c Size of the crack length c above which the calculation stops This is one of the criteria to stop the calculations and it can be used for instance to calculate the number of cycles that it takes to reach a certain crack size If you don t want to use this criterion just set it to a very high value e g greater than the specimen width w value 68 Typical Database Option Option to use typical KI 2D equations faster computation time or equations retrieved from the Equations Database Open KI Button Shows the typical 2D equation window where the user can choose from different KI equations Equation Name List of names of the available KI 2D stress intensity factor equations from the Equations Database Just click on the desired name to load its Formula Formulas Formulas of the KI 2D stress intensity factor equation in a and c loaded from the Equations Database through the Equation Names list The for
48. 2 M Pi d 3 Assuming that the bending moment M is equal to the applied force times the beam length L replace the letter M by the letter L you don t need to include the force since this expression will multiply the force history in the Loading Window at the end of the calculation 3 Highlight the expression Kf that is beside the bending stress expression and click on the Kf button The Calculate Typical Stress Concentration Factor Kt window will appear Type in the specimen dimensions and click on the filleted shaft group and on the figure corresponding to bending on a filleted shaft The values of Kt and q will be calculated and the resulting fatigue stress concentration factor Kf will be displayed Click on the OK button to return to the Smart Calculator and automatically replace the expression Kf in the Formula field by the value of the calculated Kf 4 Highlight the letter t in the equation using the mouse by clicking the mouse button and dragging over the letter and press the Torsion button The letter t will be replaced by the torsion stress equation for a circular shaft 16 T Pi d 3 Assuming that the torsion T is linearly related to the applied forces by a constant t replace the letter T by the letter t you don t need to include the force since this expression will multiply the force history in the Loading Window at the end of the calculation 5 Highlight the expression Kf that is beside the torsion stress expression and click on th
49. 7 2 00E 00 Elber E 00E 01 walker CTOD 1 48E 01 mm Wheeler i30E n0 M Wheeler 505 01 0 AK SH Curve BH Curva da dH Curva Standard Estimated SN Curve Shows the estimated SN curve of the material this plot ignores the values of the endurance limit modifiers ka kb kc kd and ke The graph is only updated after the property changes are saved To expand or shrink the graph just double click on it Sf Uncorrected Endurance Limit set it to zero if you don t want any elbow in the SN Curve b SN Exponent of the SN Curve N S b c c SN Coefficient of the SN Curve N S b c Nf Location of the SN curve elbow belb Value of the b exponent of the SN Curve after the elbow set belb 0 to ignore this option Calculate b c Button Experimental Points Command Loads the values of the parameters b and c of the SN curve N S bzc from the Experimental Points Window directly into the current window Calculate b c Button From eN Curve Elastic Component Command Calculates the constants of the SN Curve N S b c by making it coincident with the elastic part of the eN Curve defined by the eN Curve parameters Sigmaf and b This estimate is based on the principle that both SN and eN methods should predict the same damage for high cycle calculations After the calculation the estimated b and c values are color coded in red 28 Calculate b c Button For Steels and Alumina Command Ac
50. Caffin M ansan Morrow El Morrow EP Unle a 0 damage na damage damage na damage no dan 200 1 2 1992 06 3 3BBBE 06 4 6232E 06 4 1 113 1 3 1 2 1003E 06 3 6534E 06 10 250 4 5039E 06 5 2 r 04E 06 93 3611E 06 1 0542E 05 11 3 4 BBE LB 3 3835E 06 b 2846E 06 B 309E 06 DAMAGE 1 0847E 05 1 2825 058 21712545 27927E 05 BLOCKS B 322E404 B 7 80E 04 B 4 61E 04 B 3 56E 04 38 Logbook iO xj Last Calculation Time 3s 3 6 00 12 53 TL 20 n E cd m Standard Toolbar Main Toolbar of the ViDa Main Window with buttons for the most common commands To see the ToolTip of each button just point at it with the mouse and wait for 2 seconds Edit Toolbar Toolbar with buttons for editing the current Loading Window You can for instance Add or Delete one or more rows from the Loading Window This Toolbar has essentially the same functionality as the Edit menu To see the ToolTip of each button just point at it with the mouse and wait for 2 seconds You can hide this toolbar using the View menu Material Toolbar Toolbar with shortcuts for the Material Window Equation Window and the Find Material and Browse Material Windows This toolbar also contains a list with all available Materials see below To see the ToolTip of each button just point at it with the mouse and wait for 2 seconds You can hide this toolbar using the
51. Da recognizes retardation and even crack arrest effects in crack growth calculations To consider retardation effects go to any crack growth window and type the Wheeler exponent of the material on the Retard Effect field To consider crack arrest effects check as well the M W Modified Wheeler option Crack growth retardation effects are modeled using the Wheeler approach where each instantaneous crack growth rate da dNi is multiplied by a retardation factor which is a function of eventual stress overloads The Modified Wheeler M W approach is very similar except that it corrects deltaKi which can predict crack arrest ViDa predicts the behavior of surface cracks by calculating crack growth both sideways and in depth considering the changes in crack shape and the retardation and crack arrest effects Click Bidimensional Crack Growth on the Life menu and choose among Semi Elliptic Corner or Internal cracks The bidimensional crack model in ViDa assumes corner cracks to be a quart ellipsis surface cracks a semi ellipsis and internal crack a full ellipsis recognizing that these cracks normally change their shape ratio during the propagation i e despite remaining elliptical they can vary the a c ratio at each loading cycle You can choose among several different plots in the Bidimensional Crack Growth calculations For instance you can plot KI in depth against KI in the width direction or even plot the shape of the crack fronts It
52. Deletes the selected equation permanently from the database Update Button Updates all the equation data from the current Tab to the database Note that you need to use this command for the changes to become effective for further calculations 37 Undo All Button Returns all unsaved equation data to its original values Edit Button Edits the selected figure using the graphical software defined in the File Locations tab of the Options window Exit Button Exits the Equations Database window and returns to the Main Window Note that you need to update the changed equations for them to become effective for further calculations 38 Calculate Life SN Extended Window Calculates the damage and remaining life using the SN Method and the loading history from the Main Window The SN method is recommended only if the stress strain history at the critical point normally a notch root is elastic The user can input the specimen characteristics to determine the values of ka kb kc kd and ke the fatigue strength modifiers due to surface finish size loading temperature and other effects alter the material SN curve equation calculate and input stress concentration factors define user SaSm diagrams and many other options Some of the default data in this window comes from the Materials database and the rest is maintained from your last calculation A simplified Calculate Life SN window recommended for beginners is also available by
53. Editing an current equation just type the alterations in the equation and click on the Update button making the changes effective and available for further calculations Creating a new equation on the last row of the table enter the name of the new equation which must be different from all others since all equations must have an unique name in the database Type in the equation Formula click on the Equation Interpreter Help button to get more information about the equations syntax and the optional Source and Memo fields Finally click on the Update button to create the new equation Deleting an equation click on the row of the equation you want to delete and click on the Delete button How do I Handle Tridimensional Stress Histories Rosette Data ViDa lets you calculate equivalent stresses or strains for a list of 3D stresses with normal and shear components or for a list of strain triplets measured from a rectangular or delta Rosette in the Calculate Tridimensional Equivalent Stress and Calculate Rosette Equivalent Stress windows Use the Calculation Type tabs to toggle between 3D or Rosette components These equivalent stresses can then be used in the Loading Window for damage and crack growth calculations 1 For 3D stresses go to the Calculate Tridimensional Equivalent Stress window and type in the stress or strain tensor components XX YY ZZ XY XZ and YZ in the Tridimensional Table You can choose between Stress or Strain
54. Experimental Points Tables from SI to English units MPa gt ksi MPaVm gt ksiVin mm cycle in cycle Note however that only the numerical values are changed so if you want to perform calculations in English units you need to select the Tools Options command from the Main Window and choose English Units from the Units tab Table ksi gt MPa Command Converts the numerical values of all the 3 Experimental Points Tables from English to SI units ksi gt MPa ksiVin gt MPaVm in cycle mm cycle Note however that only the numerical values are changed so if you want to perform calculations in SI units you need to select the Tools Options command from the Main Window and choose SI Units from the Units tab 22 Open Material window Shows a list of all materials in the database or the ones that matched a query from the Find Material window Just click on the desired material to load the data Materials List Su 471 Su 414 Su 354 Su 4596 Su 696 Su 441 5u T392 Su 441 Su 395 Su 441 Su 446 Su 441 Su 450 Su 483 Su 503 Su 54 Su 566 Su 454 Su 454 Su 464 Su 571 Su 552 5u 848 Su 4 76 Su 1605 Su 2195 121 180 130 124 1 00 Elc 130 1 130 Elc 130 127 128 Klc 107 Elc 130 12 124 103 1 99 1 99 48 18 1 95 111 44 1 00 Elc 6 Elc 00 1
55. File Save Command Saves the loading history alt or pic to a file File Save As Command Saves the loading history alt or pic as a new file File Save All Command Saves ALL open windows to their respective files File Print Preview Command Prints the current Loading Window Datasheet File Print Command Prints the current Loading Window Datasheet File Export Command Saves the loading history alt or pic as a CSV Comma Separated Values csv file File Recent Files Command Opens one of the 4 most recent loading files that you ve been working on A list of these 4 files are shown on the menu will their full path File Exit Command Asks if you want to save your changes from all modified Loading Windows and exits ViDa 16 Edit Menu Cut Copy Paste Insert Paste Delete Rows Insert Rows Replicate Block Fill Cells Reset Number of Rows Filter Check Peaks Valleys Convert Multiply by Constant Add Constant Edit Cut Command Copies to the Clipboard and clears the values of a group of cells from the Loading Window The cells to be cut are defined by the highlighted cells in the table To highlight them just drag the mouse while pressing the left button or press the SHIFT key while using the keyboard arrows You can Paste these values for instance on an Excel worksheet Edit Copy Command Copies to the Clipboard the values of a group of cells from the Loading Window Th
56. Life Welded Structures command The Calculate Life of Welded otructures window will appear 2 Click on the drawing of the desired weld joint Its class and description will be shown on the bottom of the window and press OK The damage and remaining life time are almost instantly displayed on the 2 bottom rows of the Loading Window Also Damage x Event and Accumulated Damage x Event graphs are plotted to better display the results Drawing Elastoplastic Hysteresis Loops To achieve reliable results when calculating fatigue damage under complex loading by the eN strain life method it is necessary to draw the correct elastoplastic hysteresis loops which act at the critical notch root 1 In the Main Window make sure that the Extended Modeling option is chosen using the Tools Options command This option is required to let ViDa calculate and plot hysteresis loops 2 Choose the Life eN Method command and the Calculate Life eN window will appear 3 Turn on the Calculate Hysteresis Loops option and check if the Loop Corrections option is checked as well 4 Press the OK button The hysteresis loops for the loading history are calculated and plotted The damage and remaining life time are almost instantly displayed on the 2 bottom rows of the Loading Window Also Damage x Event and Accumulated Damage x Event graphs are plotted to better display the results Calculating Crack Growth To quantify fatigue damage in cracked structures
57. MPa commands Since ViDa only saves the numerical values from each table the user must be careful about which units the table values represent 5 Choose the Fit eN button to fit the eN experimental data points using a least squares method for a Coffin Manson equation The 4 eN curve constants are calculated and the fitted curve is plotted on the eN graph as Log e x Log N the Young modulus E comes from the monotonic data 6 Choose the File Save command if you want to save the experimental data points and the calculated constants to the Materials database These points will be associated to the current material T f you want to use the calculated eN curve constants in further calculations you need to copy them from the Experimental Points tab and paste on the eN curve parameters on the Fatigue and Fracture tab 8 If you copied any fitted parameters as described in step 7 you need to save the changes for them to become effective and available for further calculations Use the File Save command to save the changes 97 How do I Use the Equations Database In the Kt KI or da dN Equations Database window it is possible to add delete or change data of a specific equation You can alter the equations just by clicking on the desired field and entering the new data Note that this new data will only be effective after you save it using the Update button The following are some common procedures in the Equations Database window
58. Material window where the user can browse all materials from the database showing all their properties You can rearrange the columns by dragging the column title with the mouse and dropping it over the desired position ViDa automatically sorts the table by the first column so if you want to order the materials e g by their Su just drag and drop it on the first column You can also resize the columns and all your layout changes are saved So just customize your table start browsing and double click on the Materials table on the name of the material you want to load to the Material window Life Menu Rainflow Sequential Rainflow SN Method Welded Structures eN Method Crack Growth Bidimensional Crack Growth Logbook Life Rainflow Command Calculates the Alternate and Mean components of a Peak Valley history using a Rainflow counter and the amplitude Filter value Life Sequential Rainflow Command Calculates the Alternate and Mean components of a Peak Valley history using a Sequential Rainflow counter and the amplitude Filter value The Sequential Rainflow is a variation of the Rainflow that preserves as much as possible the loading order which is very useful with the eN method and crack growth calculations Life SN Method Command Goes to the Calculate Life SN window for damage calculation using the current material and Loading Window load values 19 Life IIW Method welded structures Command Goes t
59. Miner rule suggests a total damage value of 1 for the end of life but other values can be chosen by the user 49 Reliability Factor R Reliability of the calculation ViDa uses by default a 97 7 reliability as defined by the IIW for the Welded Structures calculations but the user can also choose another reliability factor Consider SN Curve Elbow Option Option to consider the elbow in the SN curve which defines no fatigue damage for number of cycles greater than the fatigue limit N If this option is off then the elbow is ignored melb Value of the m exponent of the Weld SN Curve after the elbow set melb 0 to ignore this option Weld Joint Class Class of the Weld Joint to be used in the life calculation according to the International Institute of Welding IIW data The class is defined as the alternated stress applied to the specimen associated to a 2 000 000 cycles life for the weld Click on the Weld Joint buttons to retrieve the class values of common Weld Joints Weld Joint Description Description of the chosen Weld Joint Weld Joint Buttons Buttons showing typical weld joints Just click on each Weld Joint Button to load its class and description OK Button Calculates life for the chosen specimen and weld joint using the IIW Method for the Loading Window loadings and the chosen options and goes back to the Main Window Cancel Button Cancels the Weld Joint life calculation and goes back to the Main Window 50
60. Rosette components A B and C Example of a ros file for 4 loadings 4 1000 500 2000 500 1000 0 2000 2000 2000 500 500 400 CSV Comma Separated Value files csv Files containing a list of data separated by commas These files can be automatically generated from many other software such as the Instron s Wavemaker or Microsoft Excel One of the columns of these files can be loaded to the Loading Window The first row contains the titles describing each of the columns of the following rows The next rows have sequential data corresponding to the fields described in the first row Note in order to load these files to ViDa check if the List Separator from the Regional Settings Windows Control Panel is set to a comma Example of a csv file with 4 values Time Sequence Block Cycle Position mm Load kN Strain 0 1 1 1 0 087 0 37 0 0034 0 006 1 1 1 0 096 1 51 0 0019 0 008 1 1 1 0 10 3 06 0 0024 0 01 1 1 1 0 11 4 97 0 0028 Kyowa histogrammer output files 1 Output file generated from the Kyowa RHS 500A histogrammer These are rather specific files that ViDa recognizes and therefore won t be described here in this help Refer to the Kyowa RHS 500A histogrammer Manual for more information on these files Calculation Logbook files log Files containing data from all 5 tables of the Calculation Logbook window The first row contains the number of rows of each of the tables SN eN
61. Steel 121 207 424 324 200 B3 123 2 12E 02 BE 1 15 5AE 126 BHn Steel 126 207 421 314 200 121 2 11E 02 1 18E 0 1015 5 80 BHn Steel 80 207 414 228 241 66 150 2 02 1 18E 0 1018 4151 106 BHn Steel 106 200 354 250 133 130 1 7 7E 02 1 18bE 0 1018 4151 118 BHn Steel 118 207 496 2950 383 6b 124 2 48 02 1 18E 0 1018 4151 209 BHn Steel 209 202 696 5 2 153 3 48 02 1 18E 07 102044151 105 108 BHn Steel 105 203 441 260 243 130 2 21E 02 1 1 8E 0 1020 4151 108 BHn Steel 108 186 392 254 241 64 130 1 96 02 1 18E 07 1020 54AE 108 BHn Steel 108 203 441 262 241 62 130 2 21E 02 1 18E 0 1020 S 4E 111 BHn Steel 111 207 395 285 226 127 1 98 02 1 18E 07 1TO20 S 4E 131 BHn Steel 131 207 441 34b 225 b 125 2 21E 02 1 18E 0 1TO20 S 4E 143 BHn Steel 143 207 446 331 226 59 ID 2 24E 02 1 18E 0 1 20 5AE Default Steel 108 203 441 262 24 62 130 2 21E 02 1 18E 0 1 22 5A4E 137 BHn Steel 137 207 450 31 225 63 126 2 25E 02 1 18E 0 1022 S 4E 143BHn Steel 143 207 483 359 226 124 2 426402 1 18 0 1 22 5 E 149 BHn Steel 149 207 503 359 226 103 2 52E 02 1 18E 0 1 z5 Al5 a Steel 161 547 306 292 be 833 2 4 02 1 18 0 1025 4151 Steel 166 207 566 387 350 5r 838 2 046402 1 18bE 0 1030 4151 Steel 128 454 283 209 59 558 02 1 18 0 1030 4151 b Steel 128 454 283 135 59 858 1 18 07 1030754 126 Steel
62. These modifiers are then used to estimate the Piece SN Curve which is shown on the SN method window ViDa lets you define the SN curve N S bzc in ways Automatic interpolates the points N S 1000 0 9 Su and 1E6 Sf for steels b Sf Nf uses N S Nf Sf and the supplied value of b and b c Nf uses the supplied values of b c and the elbow location Nf also enabling the Calculate b and c buttons To use a SN curve with 2 different slopes in fatigue calculations enter a value different than zero for belb the b exponent after the elbow either on the Material window or on the SN method window Since both SN and eN methods should predict the same damage for high cycle calculations it is possible to estimate the SN curve parameters from the elastic part of the eN curve On the SN method window click on the Calculate b and c SN from eN Curve button 102 al 02 53 54 55 56 of 58 59 60 61 62 63 64 65 66 To automatically calculate the values of the endurance limit modifying factors ka kb and on the SN or eN method window enter the Surface Finish the Type of Loading the Effective Diameter the Ultimate Strength Su and the Operating Temperature of the piece You can also alter these modifying factors manually To calculate the effective diameter of circular rectangular channel or l beam cross sections under bending click on the Effective Diameter
63. Window Calculate Effective Diameter Window Calculate Typical Stress Concentration Factor Kt Window Calculating Stored Stress Concentration Factors Kt Calculate Notch Sensitivity q for Steels and Alumina Window Calculate Life of Welded Structures Window Calculate Life eN Extended Window Calculate Life eN Simplified Window Crack Growth da dN Extended Window Typical da dN Curves Window Typical Stress Intensity Factor Windows Crack Growth da dN Simplified Window Bidimensional Crack Growth da dN and dc dN Window Calculation Logbook Window Calculate Equivalent Stress Window Tridimensional Peaks and Valleys Tab Rosette Peaks and Valleys Tab Smart Calculator Window Options Window Multimedia Window Tip of the Day Window 13 Main Window The ViDa Main Window is where the user inputs the loading history in the Loading Windows and where the calculation results and plots are shown iba 2001 isual Damagemeter for Windows File Edit View Data Toole Window Help 11 sae as d 94 ve Sp 262 5 441 Klc 130 gt 1020 54 Default C ViDa2001 Data Complex pic Alternate M ean IS Stress MPal Loading Time 0 5 PeakA Peak A Era eR TH TTE 400 Alternate Mean eti Stress MPa Loading Time 0 200 Peak Valley eti Strain pe Filter 0 0 200 B ANNA Event Peak V alley
64. a Help file and shows its Search engine Help Multimedia Command 20 Loads the Multimedia window with links to the Textbook Fatigue Design under Complex Loading Published Papers and video animations Help Register Command Loads the ViDa Registration window This window shows the Software Code associated to your computer which you ll need to inform in order to receive the Liberation Key After receiving your key you should type in the Liberation Key your Name and click Register ViDa becomes fully functional after registering Help Tip of the Day Command Loads the Tip of the Day window which shows tips on working with ViDa This window is loaded every time you run ViDa if the Show Tips at Startup option is selected in the Options window Help About ViDa Command Shows the About window with the credits and version of the program 21 Handling all ViDa Graphs With these commands you can work with any graph shown in ViDa This applies to the graphs on the Loading windows on the Material window on the SN eN and da dN calculation windows on the Equivalent Stress window and on the Calculate Kt and q windows 1 You can expand or shrink almost any graph by double clicking on it 2 You can select individual points of the graph by clicking the mouse on it The values of its coordinates will automatically appear on the Main Window Status Bar as well as on the graph ToolTip the little yellow box that appears by the
65. a by default plot them for a life associated with the elbow of the SN curve 1 000 000 cycles for most steels By clicking on the menu command Graph Define Life for SaSm the user can change this default plotting value to see the damage curves for any desired life Use Kt in Smean Option Option to apply the stress concentration factor on the mean stress not only on the alternate component Some theories suggest that the Kt value should only be applied to the alternate stress and ignored for the mean so in this case just turn this option off Plot Soderberg Option Option to plot or not to plot the data calculated using the Soderberg damage curve Since Soderberg is very conservative it calculates damages much greater than the other curves would predict which makes difficult the visualization in the graphs In this case just turn this option off and only the Goodman Gerber and user damage curve results are plotted Initial Damage Initial damage value before the loading history using the Palmgreen Miner rule End of Life at Damage Total damage value that characterizes failure of the specimen The Palmgreen Miner rule suggests a total damage value of 1 for the end of life but other values can be chosen by the user Consider Residual Stresses Option Option that considers residual stresses in the SN life calculation The program needs to draw hysteresis loops in order to consider residual stresses accurately which increases the complexit
66. a same life This equation has the form Sa Sf 4m Sm Sref n 1 Sf being the corrected endurance limit Sf ka kb kc kd ke Sf and the user can define any values for m n and Sref In the Goodman curve for instance the values are m n 1 and Sref is the ultimate strength Su User Damage Curve Name Name of the user defined SaSm damage curve Alternate Stress Exponent Alternate stress exponent m of the user defined SaSm damage curve Sa Sf 4m Sm Sref 4n 1 Mean Stress Exponent Mean stress exponent of the user defined SaSm damage curve Sa Sf 4m Sm Sref 4n 1 Reference Mean Strength Reference mean strength Sref of the user defined SaSm damage curve Sa Sf 4m Sm Sref 4n 1 In general its value is chosen as Su or Sy Sm lt 0 Slope of the SaSm curve when the mean stress is negative This slope is measured as a percentage of the Goodman curve slope If 0 is chosen then the SaSm curve is flat for negative mean stresses When this percentage is increased the user is valorizing the beneficial influence of compressive mean stresses which can extend life User Damage Curve Help Button Shows a help window with some basic explanations about the User Damage Curve 4 SaSm Graph Graph showing the damage curve relating alternate and mean stresses Sa and Sm pairs that cause the same damage for different models Goodman Gerber Soderberg and the user defined damage curve Since these curves can be plotted for any reference life in cycles ViD
67. ab and use the File Save command File Menu Open Save Save as New Find Browse Delete Exit File Open Command Goes to the Open Material window which shows a list of all available materials Just click on the name of the desired material to load it File Save Command Saves all the material properties to the database and updates all 7 graphs in the Material window The black red measured estimated properties color coding is also saved in the database It also saves the experimental points and calculated properties data for this material in the database Note that you need to save the changed properties for them to become effective and available for further calculations File Save as New Command Creates a new material in the database with all the current properties and experimental data and updates the 7 graphs in the Material window Note that each material must have an unique name so you must change the Name field before saving as new File Find Command Goes to the Find Material window where the user can search for materials by their type steels alumina etc or by any property ranges e g materials with Su between 600 and 800 MPa or combinations of them You can also sort the matching materials by any property File Browse Command Goes to the Browse Material window where the user can browse all materials from the database showing all their properties You can rearrange the columns
68. ake sure that the history in the Loading Window is expressed as a Peak Valley sequence by clicking on Peak Valley in the Sequencing Option enter a value for the amplitude Filter optional and then click Life Rainflow The Loading Window will then contain the Rainflow filtered Peak Valley history 3 Click on Life Welded Structures to enter the Calculate Life of Welded Structures window 4 Enter the Calculation Title in order to further identify this calculation in the Calculation Logbook window 5 Enter the values of the Weld Joint class and the exponent m from the International Institute of Welding IIW equation N cycles 2 000 000 weld class applied stress m Enter also the values of the Fatigue Limit N which is the number of cycles above which there is no fatigue damage for the Weld Joint and the End of life at damage field which is the total damage value that characterizes failure of the specimen The Palmgreen Miner rule suggests a total damage value of 1 for the end of life but any other value can be chosen by the user You can also choose a value for the reliability of the calculations the default value defined by the International Institute of Welding is 97 7 The default values of m and N are 3 0 and 5 000 000 and the class value depends on the weld joint detail 6 Click on the button of the desired weld joint and the chosen weld joint class and description will be shown on the bottom right of the window Press the OK
69. and estimate their parameters use the Experimental Points tab Refer to the topic How do Handle Experimental Data Points 96 How do Handle Experimental Data Points The user can store experimental data points for the currently selected material SN eN and da dN Paris or Elber curves can be automatically fitted to the experimental points and the calculated properties data can be used for future calculations The following example shows how to store eN Curve data points and how to calculate the eN Curve parameters using a least squares fitting 1 Go to the Experimental Points tab on the Material Window 2 Click on the eN Tab to switch tab to the eN curve experimental points table 3 With the help of the Table menu type in the eN table the number of reversions 2N and associated strain and stress amplitudes de 2 and dS 2 ViDa needs the value of the stress amplitudes dS 2 in the least squares fit because the eN Curve contains 4 parameters to be calculated You can also load a CSV Comma Separated Values file into the table by using the Table Import command Note that ViDa ignores the first row of the CSV file assuming that it just contains the column titles and the file must have exactly 3 columns for the eN table only for the SN or da dN tables it must contain 2 columns 4 The user can convert the values from ALL 3 tables from SI to English units or vice versa by using the Table MPa gt ksi or the Table ksi gt
70. atabase consisting of the ViDa mdb file Make sure that this file is present in the same directory as the ViDa exe file The user doesn t need to have Microsoft Access since all data can be entered through the ViDa program 109 Input File Formats This topic shows a description of the 8 file formats used by ViDa These files are Peak Valley files pic Alternate Mean files alt 3D Peak Valley files p3d Rosette Peak Valley files ros CSV files csv Kyowa histogrammer output files 1 Calculation Logbook files log Variables Table files var Peak Valley files pic ASCII files containing a sequence of peaks and valleys The first row contains the number of remaining rows in the file the number of events the value of the Table Option 0 for Stress values and 1 for Strain values and the Loading Time in seconds duration of ALL the loading history The remaining rows contain the values of the peaks and valleys Example of a pic file for 4 loadings expressed in strains and duration of 6 seconds 1 0 1000 500 1800 Alternate Mean files alt ASCII files containing a sequence of alternate and mean components The first row contains the number of remaining rows in the file the number of events the value of the Table Option 0 for Stress values and 1 for Strain values and the Loading Time in seconds duration of ALL the loading history The remaining rows contain the values of the alternate and
71. aterial These values are tabulated referencing Rolfe Barson rough estimates After the calculation the estimated A and m values are color coded in red Calculate Elber Button Experimental Points Command Loads the values of the A and m coefficients of the Elber da dN equation da dN A deltaK deltaKth m from the Experimental Points tab in the Materials Database directly into the current window 29 Experimental Data Tab Material Local vida mdb File Edit Table 11 alal mlale Belo Hame 1020 5AE Default k Experimental Data epsilon Sigma MPa i 5 E 03 22 278 02 1 01 4 BDE 02 5 D5E 02 5 50 02 5 BDE 02 0 00 6 20 02 B 15E 02 0 E 00 6 50E 02 6 80E 02 6 75E 02 7 02E 02 6 90E 02 00 Sigma MPa 8 ra zm 0 0 01 0 0 3 04 1 04 07 e m m Hardening Monotonic Cyclic n 0 00E 00 n 0 00 00 k 0 00 00 k 0 00 00 ss ss Fit Monotonic Fit Cyclic Experimental Points Tables Tables where the user can input experimental points SN eN da dN Tabs Switches tab to the SN eN or da dN curve experimental points table Hardening Tab Switches tab to the hardening curves experimental points table SN Graph Log S x Log N curve graph plotting the experimental points and or the fitted curves from the calculated properties data Note that the graph is only updated after you save the data using the File Save command eN Graph Log e x Log N
72. ation window where the user can choose from different equations Equation Name List of names of the available Kl stress intensity factor equations from the Equations Database Just click on the desired name to load its Formula Formula Formula of the KI stress intensity factor equation loaded from the Equations Database through the KI Equation Names list The formula can also be edited by the user and even added to the Equations Database using the Save As New button Calculate Kl Button Calculates the value of KI stress intensity factor for the current Formula and Variables Table values The user is asked to input the stress variation deltaSigma S for which he wants to calculate the KI value Save As New Button Adds the KI stress intensity factor equation present in the KI Formula field to the Equations Database The user will be asked to enter a name for this new equation KI Chart Chart containing the geometry factor beta for each crack size which will be interpolated to calculate KI New Open Save Number of Rows Buttons Commands to create a new open save or define the number of rows of the charted KI table The KI charts can be loaded from ki files or from files generated by the Quebra Finite Element software View Button Views the drawing of the specimen generated by the Quebra Finite Element software 59 Retardation Options Tab SE T METTI GUB D ETBLI Calculation title da dM Curve Reta
73. button on the SN or eN method window ViDa uses this diameter to automatically calculate the fatigue endurance limit modifying factor kb the size factor A better surface finish ka increases the fatigue endurance limit of a piece less imperfections Note that itis the surface finish of the critical point where the damage calculation is made that matters Note also that the surface finish does not affect the fatigue life when significant plastic deformation is involved eN The endurance limit modifier kb the size factor despite being widely used can be questioned under the argument that since size effects are caused by stress gradients the size that matters should be the notch root which is already considered by the notch sensitivity q ViDa lets you choose to or not to use kb omall specimens high fatigue limit modifier kc at lower temperatures high kd have greater fatigue endurance limit than large ones which have greater surface area subject to imperfections and high stresses at higher temperatures easier dislocation propagation Be careful not to include the stress concentration factor Kt or Kf in the value of the endurance limit modifier ke Remember that Kt is a parameter related to the applied stresses while ke is related to the specimen resistance they re two different concepts ViDa considers the mean load effect in the SN method calculations as predicted by the Soderberg Goodman and Gerber damage models and even
74. by dragging the column title with the mouse and dropping it over the desired position ViDa automatically sorts the table by the first column so if you want to order the materials e g by 3l their Su just drag and drop it on the first column You can also resize the columns and all your layout changes are saved So just customize your table start browsing and double click on the Materials table on the name of the material you want to load to the Material window File Delete Command Deletes the current material permanently from the database The default material is then automatically loaded File Exit Command Exits the Material Window and returns to the Main Window Note that you need to save the changed properties for them to become effective for further calculations Edit Menu Clear All Properties Clear Estimated Values Estimate using Nominal Values Edit Clear All Properties Command Sets ALL the material properties to zero Note that the changes are only effective after you click on File Save or File Save as New commands Use the Edit Clear All Properties command and then File Save As New to create a new material from scratch Edit Clear Estimated Values Command Sets the estimated color coded in red material properties to zero Note that the changes are only effective after you click on File Save or File Save as New commands Use this command to discard the estimated non reliable properties either to esti
75. by their price The next example will show you how to choose the material you re working with 1 From the Main Window choose the Data Material command The Material Window will appear with the properties of the current material 2 Choose the File Open command A list with all the materials in the database will appear 3 Click on the name of the desired material Its done All the stored properties for that material will appear in the Material Window Even experimentally measured points for this material if any will be loaded and available through the Experimental Points tab If you want you can change some of the properties but you ll need to use the File Save command in order to be able to use these changes in the calculations Note that some values are written in red in the Material Window The red color denotes properties that were calculated estimated from others without having been directly measured This color can be toggled by pressing the space bar on the desired value When you return to the Main Window by using the File Exit command the name of the selected material will be displayed in the Material field and any further calculations will use its properties Calculating Life of Welded Structures ViDa calculates the damage associated to the loading history for welded structures This calculation is independent of the current Material since it depends only on the Weld Joint class 1 From the Main Window click on the
76. calculation is performed The user can also input a strain amplitude filter in microstrains Crack Growth Calculation Tips 79 To obtain the m coefficients of the Paris da dN equation da dN A deltaK m from the Rolfe Barson estimates click the Rolfe Barson button on the da dN method window These estimates are only valid for steels and they depend only on its microstructure 104 80 81 82 83 84 85 86 87 88 89 90 91 92 93 To obtain the constants of the Paris law da dN A dK m from the eN curve parameters click the From eN Curve button on the da dN method window These estimates use the assumption that the crack growth is caused by the successive breaking of tiny eN specimens each with a width da which fail when they achieve their critical damage To adjust almost any da dN curve to your experimental data fit them to the Paris and Elber laws on the Material window and select any da dN formula on the Crack Growth window Finally tune in its coefficients by interactively editing the variables and redrawing the da dN graph until it is visually compatible with the fitted Paris and Elber curves To plot a da dN equation on the Crack Growth window for different values of R Kmin Kmax right click on the da dN graph with the mouse choose Vary R and input the range of the R values and the number of curves to be plotted This plot is very useful to visualize the influence o
77. can also copy the contents of the graph in order to paste in almost any other application To expand or shrink the graph just double click on it This graph is shown only if the Show Loading Graph option is checked on the Options window Loading Histogram Graph Plots a 3D bar chart of a loaded bidimensional histogram Bidimensional histograms are loaded by opening a CSV csv or Excel xls file and turning on both the Histogram and the Mean Interval options To expand or shrink the graph just double click on it This graph is shown only if the Show Loading Histogram Graph option is checked on the Options window Damage Graph For the SN IIW and eN Methods shows the damage and for the da dN Method the crack growth associated with each event To expand or shrink the graph just double click on it Accumulated Damage Curve 2D Crack Graph For the SN IIW and eN Methods shows the accumulated damage whereas for the da dN shows the total crack growth since the first event after each event For Bidimensional Crack Growth calculations this graph shows one of the several plots that can be chosen by the user To expand or shrink the graph just double click on it Hysteresis Loops Elliptic Cracks Graph Shows the elastoplastic hysteresis loops calculated by the eN Method or one of the several plots that can be chosen by the user in the Bidimensional Crack Growth window To expand or shrink the graph just double click on it This graph is show
78. culate Kt button Stored which goes to the Smart Calculator window and calculates Kt from previously stored equations in the Kt Equations Database commands 15 Check if all options are set as desired and press the OK Button The damage and residual life will be calculated and shown in the Loading Window Note that the residual life in days depends on the Loading Time value from the Loading Window 9 How do Calculate Unidimensional Crack Growth To quantify fatigue damage in cracked structures ViDa calculates crack growth using any da dN equation specified by the user recognizing retardation and even crack arrest effects Below there is a complete list of all steps you might need to go through to perform this calculation Note that some of these steps can be skipped in some cases and also some of the options are not available in the Simplified Modeling option the symbol will denote options only available in the Extended Modeling option 1 Load a Loading History or type it in the Loading Window 2 If the loading is a sequential history you might want first to Check or Filter it Unless your loading history comes from an histogrammer as a set of Alternate Mean no of half cycle components thus not keeping order or sequencing information it is recommended to use a rainflow counter Make sure that the history in the Loading Window is expressed as a Peak Valley sequence by clicking on Peak Valley in the Sequencing Option e
79. dN Factor Option Generalization of the Wheeler Option where da dN is multiplied by an arbitrary equation defined by the user To choose from some pre defined equations press the Open button next to this option deltaK Factor Option Generalization of the Modified Wheeler Option where deltaK is multiplied by an arbitrary equation defined by the user To choose from some pre defined equations press the Open button next to this option Effective R Option Option to model crack retardation effects by changing the value of the load ratio R to an effective value To choose from some pre defined equations including the Willemborg model press the Open button next to this option 60 Minimum Overload Minimum overload percentage that activates the calculation with retardation effects If the overload percentage is smaller than this value the retardation effects are neglected Use the value 096 to always consider the retardation effects Retardation Resolution Percentage of PZol PZi on the crack growth for which the retardation factor is recalculated PZol is the plastic zone on the overload and PZi is the current plastic zone In order to speed up the calculations the program only recalculates the retardation factor when the crack has grown more than this percentage of the distance between the overload and current plastic zones Retardation Graphs Graphs of the retardation equations The top graph plots the Wheeler Modifi
80. da dN IIW and da dN 2D in that order Let these numbers be a b c d and e Then the next 6 a 1 rows in the file contain data from the SN table counting from left to right for each row in the table Then the next 7 b 1 rows contain data from the eN table the next 5 c 1 from the da dN table the next 4 d 1 from the IIW table and finally the last 6 e 1 rows contain data from the da dN 2D table When a cell doesn t contain any data then a minus character is saved Variables Table files var Contains the values of all variables of the Variables Table Each row contains of the values The 22 rows contain respectively the values of a A b B D h H n 5 t y and Z 111 References Papers 1 Meggiolaro M A amp Castro J T P ViDa Software for Fatigue Life Prediction under Complex Loadings Symposium on Experimental Stress Analysis pp 7 10 ABCM Brazilian Society of Mech Eng 95 in Portuguese 2 Meggiolaro M A amp Castro J T P Advances in Fatigue Design Automation under Complex Loadings Fracture Mechanics Seminar pp 99 118 ABM 96 in Portuguese 3 Meggiolaro M A amp Castro J T P Remarks on Fatigue Design under Complex Loadings using the eN Method IX SIBRAT COTEQ 96 pp 157 160 IBP amp ABCM 96 in Portuguese 4 Meggiolaro M A amp Castro J T P Comments on Fatigue Crack Propagation under Complex Loadings
81. dimensional histogram counting is performed on the Alternate and Mean components If not checked all Mean components are set to zero and only the Alternate components are evaluated OK Button Reads the selected field on the Fields list and returns to the Main Window Cancel Button Cancels the loading of the file and returns to the Main Window 25 Material Window In the Material window it is possible to manipulate the Materials database adding deleting changing or just selecting a specific material You can alter the material properties by clicking on the respective field and entering the new data Note that this new value will only be effective after you save it using the Material Save command You can also store experimental points for the currently selected material SN eN and da dN Paris or Elber curves can be automatically fitted to the experimental points and the calculated properties data can be used in future life calculations Values in black represent measured properties while the values in red reflect estimated properties which are less reliable To toggle the black red colors press the space bar while typing on the desired field don t forget to save the changes after General Tab Material Local vida mdb File Edit Table Delma oll SA alate Blo Name 1020 5 Default k Material Steel Source Composition 0 18 0 23 0 3 0 6 0 04 n 1 90 01 Ek
82. ding and enter the Equivalent Diameter Ultimate Strength Su the default value is loaded from the Materials Database and the Operating Temperature of the specimen These choices are used to automatically calculate the values of the endurance limit modifying factors ka kb kc and kd Note that the endurance limit is a concept originally used in the SN method but in ViDa it can also be used to correct the elastic component of the eN curve Note also that you can calculate the effective diameter for circular rectangular channel or l beam cross sections under bending using the Calculate d Effective Diameter button In this case the Calculate Effective Diameter window will appear and you click on the effective diameter of the desired cross section and bending axis The resulting effective diameter will be copied to the result field and by pressing OK you ll return to the Calculate Life eN window carrying the calculated value 7 You can alter directly the values of ka kb kc kd and ke and the value of the uncorrected endurance limit Sf prior to the calculations Note that the next time you call the Calculate Life eN window the ka kb kc and kd values will reflect the options chosen in step 6 meaning that altering their values directly will affect only the current calculation 8 Enter the parameters of the eN curve you want to use Note that in general you don t need to change these values since they re automatically loaded from the Mat
83. e calculation The 3D stresses Peak and Valley Table can be saved to or loaded from a file The calculation results can be Transferred to a new Loading Window in the Main Window m E guivalent Stress Tridimensional Peaks and Yalleps T Kt yy 11 5 tress MPa KI Eb Kt 1 Transfer C Strain pe K a t z f Kt 2 Peak V alley PUN T AT mu Equivalent 0 0 0 60 60 20 20 il 80 0 80 40 220 240 240 0 40 60 240 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Peak Valley Type Tab Lets the user choose between calculations from 3D tensor components or from Rosette measurements If the Rosette option is chosen then the Calculate 3D Equivalent Stress Window turns into the Calculate Rosette Equivalent Stress Window Tridimensional Table Table from the Calculate 3D Equivalent Stress Window containing Peak Valley stress or strain loading histories for all 6 tensor components XX YY ZZ XY XZ and YZ This table is the input for equivalent loading history calculations Table Option Option that defines if the values from the Tridimensional and Peak Valley tables represent stresses in MPa or ksi or strains in microstrains Kt Stress concentration factor for each component of the 3D tensor used in the equivalent history calculation 73 Input Output Graph Graph that shows the input 3D tensor components and the output e
84. e Equation Database To easily calculate the stress concentration factor Kt and the notch sensitivity q of typical notched and filleted bars and shafts click Calculate Kt on the Tools menu or on the SN method window select the desired specimen and enter its dimensions To add your own Stress Concentration Factor Kt Stress Intensity Factor KI or Crack Growth da dN equations which will be available for future life calculations click Equation on the Data menu To easily calculate the notch sensitivity q for steels or alumina given Su and the specimen notch radius click Calculate q on the Tools menu or on the SN method window To consider plasticity induced sequence effects in SN check Consider Residual Stress on the SN method window When yielding occurs at the notch root ViDa automatically switches to the eN method calculates the damage and induced residual stresses later added to the mean stress component and switches back to the SN method 103 67 68 69 70 Fatigue design for welded structures is actually a simplified form of the SN method based on full sized structures instead of small specimens The methodology has been normalized by the International Institute of Welding IIW and the American Welding Society AWS among others Welded structures fatigue calculations do NOT depend on the material properties They only depend on the IIW Weld Joint Class Welded structures are relatively inse
85. e Kf button Repeat step 3 but now choose the figure representing torsion on a filleted shaft Click on the OK button to return to the Smart Calculator and replace the expression Kf in the Formula field by the value of the calculated Kf The resulting expression should be similar to 32 L Pi d 3 1 41 2 3 16 t Pi d 3 1 21 2 5 6 In the Variables Table click on the L t and d variables and enter the values of the shaft length L the constant t relating the forces and torsion stresses and the shaft diameter d 7 Click on the Calculate SI button to calculate the value of the expression using SI units or Calculate ksi button for English units Note that in this specific example we didn t use any of the material properties in the Formula field so it doesn t matter if we click on the Calculate SI or Calculate ksi buttons The calculated value is a constant that can multiply the force history to convert it into an equivalent stress history see step 8 Watch out for the units if the forces in the Loading Window are in Newtons and the values of L t and d are in meters than you need to type 1E6 on the left of the formula prior to calculation since the stresses should be calculated in MPa not Pa 8 Click on the Multiply Loadings button to multiply ALL the loadings from the Loading Window by the value shown in the Result field The Loading Window will now contain an equivalent stress history with stress concentration factors already includ
86. e cells to be copied are defined by the highlighted cells in the table To highlight them just drag the mouse while pressing the left button or press the SHIFT key while using the keyboard arrows You can Paste these values for instance on an Excel worksheet Edit Paste Command Pastes the contents of the Clipboard on a group of cells of the Loading Window The cells where the values will be pasted are defined by the highlighted cells in the table To highlight them just drag the mouse while pressing the left button or press the SHIFT key while using the keyboard arrows If the size of the copied selection was greater than the current selected cells than only some of the Clipboard data is pasted On the other hand if only one cell is selected then ALL Clipboard values are pasted filling this cell and the ones to the right and below it In this case if the pasted values reach the bottom of the table new rows are added accordingly to fit ALL the Clipboard data These pasted values can be for instance cells copied from an Excel worksheet Edit Insert Paste Command Inserts new rows on the Loading Window and pastes the contents of the Clipboard on them The rows are inserted above the first selected cell on the table These pasted values can be for instance cells copied from an Excel worksheet Edit Delete Rows Command Deletes one or more rows from the Loading Window The rows to be deleted are defined by the highlighted cells in the
87. e in the Simplified Modeling Units Tab 2 ar 4 English Units Cancel pln Lets the user choose between SI and English units All the calculations and stress data from the Loading Window will be considered to be in MPa or ksi accordingly Note that the Material window will also show the material properties in the desired units even though the database actually saves the data in SI units 81 Database Tab Options Modeling Local vida mdb 5 Draft vidauser mdb m imi 5 Remote Read Only iD aXVidaaux mdb Cancel Lets the user choose the databse used in all ViDa calculations The Remote option allows the user to connect to a remote database file which could be stored on a different computer such as a server In this case the databse is considered read only the user cannot change locally the data of the remote database Note that once you change the database you need to exit and restart the ViDa program in order to make the changes effective File Locations Tab Options Modeling Graphic Editor Pbrush exe i Quebra IC VD a i uebra quebra exe 2 ees Locations of a Graphic editor program used to edit the figures the Equations Database of the Quebra Finite Element software 82 Idiom Tab Lets the user choose the desired idiom used by the entire program The options are E
88. eak Valley file pic into one or more of the columns of the Tridimensional Table for XX YY ZZ XY XZ or YZ or Rosette Table for A B or C Just select any cells from the columns where you want to load the history and press the Open Button You can also load a Rosette Peak Valley file file extension ros which contains all the Rosette Table columns A B and C or you can load a Tridimensional Peak Valley file file extension p3d which contains all the Tridimensional Table columns XX YY ZZ XY XZ and YZ see the Calculate 3D Equivalent Stress Window Save Button Saves the Rosette Peak Valley file file extension ros which contains all the Rosette Table strains A B and C In the Calculate 3D Equivalent Stress Window this command saves the Tridimensional Table as a Tridimensional Peak Valley file p3d instead Edit Button Shows a Pop up menu with commands to edit the Rosette Table For more information on the Edit commands se the Edit menu in the Main Window Calculate Button Shows a Pop up menu with the following commands Maximum Strain Minimum Strain Projected Strain Maximum Stress Minimum Stress Projected Stress Principal Direction Calculate Button Maximum Strain Command Calculates the Maximum Principal Strain for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table Calculate Button Minimum Strain Command Calculates the Minimum Principal Strain for a Rectang
89. ections significantly vary along the history using the Maximum Stress values could be too conservative Instead type an average value on the Direction field and click Projected otress or Strain An alphanumeric calculator that computes any formula using the material properties and user defined variables is available by clicking Smart Calculator on the Tools menu It features some basic Mechanics of oolids equations and computed results in SI or English units can be multiplied to the loadings in the Loading Datasheet The Smart Calculator can easily convert force histories on known geometries into stresses It has built in Mechanics of Solids equations e g bending torsion Mises it is linked to the Kt database and it lets you multiply forces on the Loading Datasheet by the calculated conversion factor obtaining the associated stress history The Input File Formats recognized by ViDa are Peak Valley pic Alternate Mean alt 3D Peak Valley p3d Rosette Peak Valley ros CSV csv Excel xls ADINA porthole port por Kyowa histogrammer 1 Calculation Logbook log and Variables Table var files The main files installed in the ViDa directory are Vida exe the main program vida ini keeps all user settings since the last time ViDa was loaded vida mdb material and equation database file vida res resource file with all the strings in ViDa in up to 7 different idioms vida hlp and vida cnt ViDa h
90. ed 9 Close the Smart Calculator window to return to the Main Window 99 Useful Tips about ViDa General Tips 1 10 11 12 13 14 15 16 ViDa has Rainflow counters Tridimensional Stress handling Rosettes Stress Concentration Factor tables and much more To know more about ViDa click Contents on the Help menu and refer to Working with ViDa Windows To change the current material without needing to go to the Material Database window just select its name from the Material dropdown list on the Main Window The Calculation Logbook is a very useful tool to compare the results of similar fatigue calculations performed under different option settings To save to a file log open or print the Logbook tables click oave Open or Print on the File menu By filling out the Calculation Title field on the calculation windows it is possible to easily compare the results of different calculations in the Calculation Logbook window ViDa accounts for the damage or crack growth in a sequential manner from the first to the last event Therefore it can quantify sequence effects such as overload induced residual stresses which can significantly alter the fatigue life of the piece To stop a calculation in progress press the ESC key To select the Simplified modeling option recommended for beginners click Options on the Tools menu and click the Simplified option on the Modeling tab All life calculation w
91. ed Wheeler da dN Factor and deltaK Factor while the bottom graph plots the Effective R for different load ratios R Plastic Zone Equation used to calculate the size of the plastic zone ahead of the crack tip for retardation calculations The user can choose among plane stress plane strain or define a different factor for the equation of the plastic zone size Sequential Option Option for sequential crack growth calculations Click on this option to let ViDa calculate crack growth sequentially from the loading history instead of using the Root Mean Square approach Krms Option Option for crack growth calculations using the Root Mean Square approach Click on this option to let ViDa calculate a RMS stress value of all the loading history and then integrate the da dN equation to calculate the crack growth instead of sequentially calculating the crack growth for each loading Note that this option cannot consider retardation effects Resolution For the Sequential option this is the increase percentage of the square root of the crack size for which the Stress Intensity Factor is recalculated In order to speed up the calculations the program only recalculates when the square root of the crack size has grown more than this percentage Typical values are in the 0 1 1 096 range For the Krms option this resolution is the integration step of Simpson s integral rule Help Button Shows a window with some information about the
92. elp and table of contents files The word fatigue originated from the Latin expression fatigare which means to tire Even though it has become a terminology in engineering vocabulary a long time ago its first descriptive definition was published in 1964 in the General Principles for Fatigue Testing of Metals in Geneva Griffith s pioneering work in 1921 with brittle materials such as glass originated all modern theories of fracture in metals However Griffith was fired because his employer never understood why a metal researcher was working with glass specimens Paris one of the fathers of LEFM was the first to suggest that crack growth could be related to the stress intensity factor but his original paper was not accepted by any leading journal in his field He ended up publishing his famous paper in 1961 on his university s news bulletin Trend in Engineering The fatigue failures of the jet aircraft Comet which led to several accidents in the 1950s heavily obstructed the prominent role played by the British aircraft industry It is widely believed that this fatigue problem served as a catalyst in the emergence of the rival Boeing in USA as a world leader in commercial aviation To see who s behind ViDa click the authors names on the About window 106 CHAPTER 5 Advanced Issues This chapter covers a variety of topics ranging from troubleshooting most common problems to viewing details on the ViDa input f
93. equation defined by the user To choose from some pre defined equations press the Open button next to this option Effective R Option Option to model crack retardation effects by changing the value of the load ratio R to an effective value To choose from some pre defined equations including the Willemborg model press the Open button next to this option Minimum Overload Minimum overload percentage that activates the calculation with retardation effects If the overload percentage is smaller than this value the retardation effects are neglected Use the value 0 to always consider the retardation effects Retardation Resolution Percentage of PZol PZi on the crack growth for which the retardation factor is recalculated PZol is the plastic zone on the overload and PZi is the current plastic zone In order to speed up the calculations the program only recalculates the retardation factor when the crack has grown more than this percentage of the distance between the overload and current plastic zones Retardation Graphs Graphs of the retardation equations The top graph plots the Wheeler Modified Wheeler da dN Factor and deltaK Factor while the bottom graph plots the Effective R for different load ratios R Plastic Zone Equation used to calculate the size of the plastic zone ahead of the crack tip for retardation calculations The user can choose among plane stress plane strain or define a different factor for the
94. equation of the plastic zone size Sequential Option Option for sequential crack growth calculations Click on this option to let ViDa calculate crack growth sequentially from the loading history instead of using the Root Mean Square approach Krms Option Option for crack growth calculations using the Root Mean Square approach Click on this option to let ViDa calculate a RMS stress value of all the loading history and then integrate the da dN equation to calculate the crack growth instead of sequentially calculating the crack growth for each loading Note that this option cannot consider retardation effects Resolution For the Sequential option this is the increase percentage of the square root of the crack size for which the Stress Intensity Factor is recalculated In order to speed up the calculations the program only recalculates when the square root of the crack size has grown more than this percentage Typical values are in the 0 1 1 096 range For the Krms option this resolution is the integration step of Simpson s integral rule Help Button Shows a window with some information about the square root of the crack size criterion 70 Graph 1 Option Option to plot or not the Damage Curve 2D Crack Graph in the Main Window Graph 1 Data List of the fields that can be plotted in the Damage Curve 2D Crack Graph in the Main Window after the bidimensional crack growth calculations Graph 1 Sampling Sampling ra
95. er data and returns to the Material window z b and for SN curve Steels M cycles 3 MPa 1000 0 3 A 441 5 1000000 220 5 5f X JL OF Cancel Values of 2 points of the SN curve to be interpolated The default values are 1000 cycles for 0 9 Su and 1 000 000 cycles for Sf but the user can change any of these values before pressing OK SN Graph Interpolation Data OK Button Calculates the b and c constants of the SN curve N S b c using the user data and returns to the Material Window or to the SN Method Window Cancel Button Cancels the calculation and returns to the Material Window or to the SN Method Window 36 Equations Database Window Database of Kt KI or da dN equations that can be used in calculations In this window you can add delete or change data of a specific equation You can alter the equations by clicking on the desired field and entering the new data Note that this new data will only be effective after you save it fei Equations Local vida B x Code Formula Delete Arc shaped spec single edge crack 2 sqrwZ pr a 1 1 T s 730 3 pt bending H P h 2 2h 3w 0 2 0 32 a w 0 12 aw 2 Update a w rs arw 0 2 0 43 r 2 1 1 5 l a w 1 49 a w 2 0 73 a w 3 x x x Arc shaped spec single edge crack 2 sqrwZ pra 1 1 Lindo All 800 3 pt bending H P h 2 2h 4w U 23 D 567a7w 0 377
96. ere the user can choose from different equations Fit Button Automatically adjusts the constants of the Typical da dN equation to the database values of Paris and Elber of the current material da dN Equation Name List of names of the available da dN equations from the Equations Database Just click on the desired name to load its Formula da dN Formula Formula of the da dN equation loaded from the Equations Database through the da dN Equation Names list The formula can also be edited by the user and even added to the Equations Database by using the Add button You can also easily tune in the coefficients of the da dN Formula by interactively editing the Variables Table and using the Graph Redraw command until the curve is visually compatible with the Paris and Elber curves in the da dN graph Calculate da dN Button Calculates the value of da dN for the current Formula and Variables Table values The user is asked to input the stress intensity factor range deltaK and the ratio R Kmin Kmax for which he wants to calculate the da dN value Save As New da dN Button Adds the da dN equation present in the da dN Formula field to the Equations Database The user will be asked to enter a name for this new equation Equation Interpreter Help Button Shows just for reference a window with the equations syntax and all the material properties that can be literally used in the equations 67 Variables Table Table containing variables tha
97. erials Database and the value of the elastic exponent b is corrected when you alter any ka kb kc kd or ke values You can also calculate the values of the eN Curve parameters or retrieve them from the Materials Database by using the Calculate b c button commands Right click on the eN curve graph and choose Redraw to see the changes in it 90 9 Enter the value of the End of life at damage field This is the total damage value that characterizes failure of the specimen The Palmgreen Miner rule suggests a total damage value of 1 for the end of life but other values can be chosen by the user 10 Choose which Strain concentration theory is to be used when stress concentration factors are present Linear theory considers Ke Kt strain concentration Ke is equal to Kt while Neuber theory uses Ke Ks Kt 2 11 Choose if you want to Consider the SN Curve Elbow applied to the elastic component of the eN Curve This option lets the user neglect the damage associated to loadings under the endurance limit Sf Sf ka kb kc kd ke Sf from the SN theory Right click on the eN curve graph and choose Redraw to see the changes in it due to the elbow 12 Choose if you want to calculate hysteresis loops in the eN calculations with the Calculate Hysteresis Loops option This option is highly recommended for complex loadings since not calculating the hysteresis loops in general leads to unrealistic and probably non conservative calculated strain
98. es of deltaKth Klc A and m from Paris law A and m from Elber law and p from Walker and Modified Walker laws prior to the calculations In general you don t need to change these values since they re automatically loaded from the Materials Database for the current material Note that the next time you call the Bidimensional Crack Growth da dN and dc dN window these properties will be loaded again from the Materials database meaning that altering their values will only affect the current calculation You can also calculate or retrieve the values of A and m from either Paris or Elber laws from the Materials Database by using the Calculate A m Paris or Elber buttons Right click on the da dN curve graph and choose Redraw to see the changes in it 7T Choose another da dN equation that can be used in the crack growth calculation besides the Elber and Modified Walker equations from a list of equation names loaded from the da dN equations database The chosen equation will be displayed in the Formula field Right click on the da dN curve graph and choose Redraw to see the changes in it 8 You can directly alter the formula for the chosen equation in the Formula field click on the button for information on the available functions from the equation interpreter Note that the next time you call the Bidimensional Crack Growth da dN and dc dN window this formula will be loaded again from the equations database meaning that directly alterin
99. ette Equivalent Stress Window containing Peak Valley strain loading histories in microstrains for all 3 components A B and C This table is the input for equivalent loading history calculations Rectangular Rosette Tab Option to consider Rectangular Rosettes in the calculations The drawing shows the locations of the A B and C strain components Delta Rosette Tab Option to consider Delta Rosettes in the calculations The drawing shows the locations of the A B and C strain components 75 Poisson Poisson coefficient of the current material used to transform the Rosette strain history into an equivalent history The default Poisson coefficient is loaded from the Materials Database but it can be changed by the user prior to the calculations E Young Young modulus of the current material used to transform the Rosette strain history into an equivalent history The default Young modulus is loaded from the Materials Database but it can be changed by the user prior to the calculations be careful with the units Direction Direction to which the stresses or strains will be projected using the Calculate Button Projected Strain or Stress commands from the menu The direction is measured counter clockwise in degrees starting from the X axis see Rectangular and Delta Rosette drawings Output Graph Graph that shows the calculated equivalent Peaks and Valleys New Button Clears the Rosette Table Open Command Loads a P
100. etup You can only install ViDa if you have Windows 95 or later or Windows NT 4 0 or later Installing ViDa Insert the ViDa disc into the CD ROM drive If autorun doesn t start double click AUTORUN EXE in Explorer Click Install on your screen and follow the instructions When you run ViDa for the first time you ll see the screen below Just click on the idiom of your choice and ViDa starts running NOTE you must register ViDa to make it fully functional If you have installation problems please refer to the Troubleshooting section Once you have installed ViDa read the License Agreement in the LICENSE TXT file You must accept the terms of the License Agreement before you can use this product The following files are installed in the application directory ViDa2002 by default ViDa exe the main program ViDa ini contains all user settings since the last time ViDa was loaded ViDa mdb ViDa database file ViDa hlp and ViDa cnt ViDa help file and table of contents file Data directory sub directory containing examples of loading history files Media directory sub directory containing all sounds videos and slides from ViDa Figures directory sub directory containing all KI da dN and Kt figures The remaining files are Windows resources files which are installed in the Windows System directory 10 Viewing the Textbook Fatigue Design under Complex Loading The textbook Fatigue Design under Complex Loading
101. f R on crack growth for each da dN equation The Critical Stress Intensity Factor Klc the amount of energy absorbed during a standard Charpy test and the value of the critical CTOD Crack Tip Opening Displacement are all measures of fracture toughness Traditional Rainflow counting of the loading history alters its original sequencing and in consequence the calculated crack growth It is strongly recommended to use instead the Sequential Rainflow counter before any crack growth calculations To calculate crack growth sequentially instead of the RMS approach click on the Sequential tab on the Crack Growth window The crack increment per half cycle is then assumed to be dai f deltaKi Ri 2 where deltaKi and Ri are the respective stress intensity range and loading ratio and f is the crack growth law To calculate crack growth using the Root Mean Square approach click on the Krms tab on the Crack Growth window A RMS stress value of all the loading history is calculated and then used to integrate the da dN equation instead of sequentially calculating the crack growth for each loading To calculate the number of cycles it takes to reach a certain crack size set a value different than zero to the Final Value field on the Crack Growth window This value is the maximum allowable crack length after which the calculation stops The Bidimensional Crack Growth window also has this feature and you can set both a and c Final Values Vi
102. f the A and m coefficients of the Elber da dN equation da dN A deltaK deltaKth m from the Materials Database directly into the current window Calculate A m Elber Button Fitted from Experimental Points Command Loads the values of the A and m coefficients of the Elber da dN equation da dN A deltaK deltaKth m from the Experimental Points tab in the Materials Database directly into the current window Modified Walker Option Option that let the user choose the Modified Walker equation da dN A deltaK deltaKth m 1 R p among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer p pWa Exponent p from the Modified Walker da dN A deltaK deltaKth m 1 R p equations The default value of p is loaded from the Materials Database but it can be changed by the user Other Equation Option Option that let the user choose the da dN equation shown in the da dN Formula field among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer Typical Database Option Option to use typical da dN equations faster computation time or equations retrieved from the Equations Database Open da dN Button Shows the typical da dN equation window wh
103. g the formula will only affect the current calculation In order to save an edited formula as a new equation you should use the Save As New button or go to the da dN Equations Database Window Right click on the da dN curve graph and choose Redraw to see the changes in it 94 9 Alter the values from the Variables Table in order to adjust the parameters of the chosen da dN equation Just click on the desired variable and enter its new value you can also load a previously saved Variables file var which contains all values from the Variables Table You can visually adjust the chosen da dN equation in order to be compatible with the Elber equation by interactively altering the variables values and right clicking on the da dN graph and choosing Redraw in order to see the changes in it You can also calculate the da dN value for a specific deltaK and R Kmin Kmax by clicking on the Calculate button 10 Enter the values of the specimen dimensions w and ti and di for Internal cracks and Ri for cracks in cylinders under pressure beside the crack drawing note that the Variables Table is not used here Enter also the crack initial dimensions a and c and also a reference final crack size for a and c for which the calculations should stop to ignore this final value criterion just set the final values to zero 11 Choose which type of bidimensional crack will be considered in the calculations by clicking on the Elliptic Corner Internal or Cyl
104. ge crack Splitting forces WOL specimen 2 9 2 a7 w gt 0 1 7 P 2 aiw Ky n 0 4554 49976a w 17 0555 a w tw l ahw T 23 1814 a w 3 13 6252 a w T2 7933 a w aj 5 256 06 PH 2 5 00 00 _ 1 006 02 00 00 _ 1 206 02 2 300E 00 _ 5 00 02 m 3 00 01 1 00E 03 m 100E 00 _ 11 00 7 p 3 50 00 _ 58 Initial Crack a Initial size of the crack length a Final Value a Size of the crack length a above which the calculation stops This is one of the criteria to stop the calculations and it can be used for instance to calculate the number of cycles that it takes to reach a certain crack size If you don t want to use this criterion just set it to a very high value for unidimensional crack growth set it to greater than the specimen width w value Width w Width of the considered specimen specimen dimension in the crack growth direction for unidimensional crack growth used in the calculation of the stress intensity factor Typical Database Charted Option Option to use typical KII or equations faster computation time equations retrieved from the Equations Database or values interpolated using a chart containing the geometry factor beta for each crack size Open KI Button Shows the typical KI equation window where the user can choose from different KI equations Open KII KIII Button Shows the typical KII and equ
105. gmaf epsilon of the curve de 2 Sigmaf E 2N b epsilonf 2N c from the Experimental Points tab directly into the current tab Consider SN Curve Elbow Option Option to consider the elbow of the SN curve which defines no fatigue damage for stresses smaller than the corrected endurance limit Sf ka kb kc kd ke Sf in the elastic portion of the eN curve If this option is off then the elbow is ignored belb Value of the b exponent of the SN Curve after the elbow set belb 0 to ignore this option Initial Damage Initial damage value before the loading history using the Palmgreen Miner rule End of Life at Damage Total damage value that characterizes failure of the specimen The Palmgreen Miner rule suggests a total damage value of 1 for the end of life but other values can be chosen by the user Surface Finish Surface finish of the specimen used to automatically calculate the endurance limit modifying factor ka the endurance limit from the SN method is used to correct the elastic component of the eN curve Type of Loading Main type of loading applied to the specimen used to automatically calculate the endurance limit modifying factor kc the endurance limit from the SN method is used to correct the elastic component of the eN curve Effective Diameter Specimen cross section diameter or effective diameter used to automatically calculate the endurance limit modifying factor kb the endurance limit from the SN method
106. gmaf True Ultimate Strength epsilonf True Ultimate Elongation R A Reduction in cross sectional area after failure in 96 n n Hardening exponents of the monotonic and cyclic curves using Ramberg Osgood equation k Hardening coefficient of the monotonic curve using Ramberg Osgood equation k Hardening coefficient of the cyclical curve using Ramberg Osgood equation Memo Additional information about the material Estimates Help Button Shows just for reference a window with all the equations used by the Calculate Estimate using Nominal Values command to estimate properties from Nominal Values These estimates are used by the ViDa program to try to fill out all the material properties that have not been measured or are not available Hardening Curve Shows the monotonic tension test and cyclic true hardening curves of the material Note the change in color marking on the graph the values of Sy and Sy The graph is only updated after the property changes are saved To expand or shrink the graph just double click on it 21 Fatigue and Fracture Tab 1 Material Local vida mdb File Edit Table 1 ala X S le pea Name E D 2 21 02 1 18E 01 standard SN curve 3 47E 33 1 00E 06 elb 10 ODE 00 Or 8 9 02 MPa 410E 01 Ez b 1 20E 01 eN c 510E m 0 02 AKth 7 00 00 4 77E 07 2 00E 00 Paris 5 33E 0
107. he Variables Table and using this Redraw command until the curve is visually compatible with the Paris and Elber curves in the da dN graph Save Command Saves the graph data as a Comma Separated Value CSV The first row contains the legend titles of each set in the graph and the following rows contain the respective data for each curve Print Command Prints the graph 23 Standard Open Save File Window This is the standard interface window for all Open and Save File commands from ViDa Open Look ir E3 Data Complex pic Decres pic channell 111 Complessmall pic Delta ros channels 13a 5 cresc ce E Retard alt si comple pic Cresc pic test alt complbig pic Data cey EJ teste log EJ L amplex p3d 5 DATA sls EJ teste log Files of type All Files hd Cancel File name Name of the file to be read Found Files Files found in the current directory defined in Folders of the extension chosen in List files of type Just double click on the desired file to choose it Files of type List with the desired file extensions Look in Shows the current directory OK Button Confirms loading saving the file Cancel Button Cancels loading saving and returns to the previous window 24 Open CSV Excel File Window This window shows the fields from the chosen comma separated value CSV file or from an Excel file xls chosen from a Standard Load File window The use
108. he desired equation to load it to the Formula field Calculate SI Button Calculates the value of the equation in the Formula field using the material properties SI units e g using SAE 1020 steel Klc in the Formula field would result in the value 250 corresponding to 250 MPaVm Calculate ksi Button Calculates the value of the equation in the Formula field using the material properties in English units e g using a SAE 1020 steel Klc in the Formula field would result in the value 227 5 corresponding to 227 5 ksiVin Multiply Loading Window Button Multiplies ALL the loadings in the Loading Window by the value shown in the Result field This command is useful for instance to transform force histories into equivalent stresses histories So if for instance the Loading Window contains forces transversally applied to a beam the user should compute the bending term 32 L Pi d 3 by setting the beam length L and diameter d in the Variables Table pressing the Calculate SI Button and finally pressing the Multiply Loadings Button Now the Loading Window contains the bending stresses note that ViDa only handles Stresses or Strains not Forces so the described conversion would be necessary The user can even consider combined bending and torsion stresses in the above example If the torque is proportional to the applied force by a constant R then you could use the Torsion expression and Mises criterion calculating the value of
109. iDa at a Glance Making your First Damage Calculation with ViDa Loading a History Changing the Material Calculating Life of Welded Structures Drawing Elastoplastic Hysteresis Loops Calculating Crack Growth Bidimensional Crack Growth ViDa Main Features ViDa is a powerful software for calculating the fatigue damage caused by complex loading It includes all the traditional fatigue design methods and introduces a series of improvements to enhance the speed and the accuracy of the numerical results e g Calculates the Fatigue Damage by the SN eN and the da dN Methods Plots the Correct Elastoplastic Hysteresis Loops calculated by the eN Method Solves the Neuber System for Stress Concentration Rainflow Counts and Racetrack Filters Complex Loading Histories Predicts the Uni and Bidimensional Growth of Fatigue Cracks Including Retardation Effects Calculates Kt q and Other Constants Required by the Various Design Methods Automatically Adjusts Experimental Curves Has Friendly and Expandable Data Banks of Materials Properties Stress Intensity Factors and More ViDa at a Glance Making your First Damage Calculation with ViDa This is a quick step by step tutorial that ll show you how to work with ViDa Even if you re not a fast typist you ll take close to the minute to make your first calculation Scenario You ve applied 100 000 cycles at 10 Hz of a pulsating 200 MPa stress on a specimen We want to calculate the
110. ic component of the eN curve kb Size factor that modifies the endurance limit smaller specimens have greater endurance limit than larger ones Note that the endurance limit and its modifying factors are originally from the SN method but in ViDa they can also be used to correct the elastic component of the eN curve kc Loading factor that modifies the endurance limit depends on the main type of loading applied to the specimen Note that the endurance limit and its modifying factors are originally from the SN method but in ViDa they can also be used to correct the elastic component of the eN curve 52 kd Temperature factor that modifies the endurance limit greater temperatures tend to bring down the endurance limit Note that the endurance limit and its modifying factors are originally from the SN method but in ViDa they can also be used to correct the elastic component of the eN curve ke Miscellaneous factors that modify the endurance limit e g corrosion Be careful not to include the stress concentration factor Kt or Kf in the value of ke since Kt and Kf are already taken care of in the stress calculation Note that the endurance limit and its modifying factors are originally from the SN method but in ViDa they can also be used to correct the elastic component of the eN curve eN Graph eN curve of the material and also its elastic and plastic components The SN curve is also plotted in order to make a comparison with the
111. ield among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer Typical Database Option Option to use typical da dN equations faster computation time or equations retrieved from the Equations Database Open da dN Button Shows the typical da dN equation window where the user can choose from different equations Fit Button Automatically adjusts the constants of the Typical da dN equation to the database values of Paris and Elber of the current material 57 da dN Equation Name List of names of the available da dN equations from the Equations Database Just click on the desired name to load its Formula da dN Formula Formula of the da dN equation loaded from the Equations Database through the da dN Equation Names list The formula can also be edited by the user and even added to the Equations Database by using the Add button You can also easily tune in the coefficients of the da dN Formula by interactively editing the Variables Table and using the Graph Redraw command until the curve is visually compatible with the Paris and Elber curves in the da dN graph Calculate da dN Button Calculates the value of da dN for the current Formula and Variables Table values The user is asked to input the stress intensity factor range deltaK and the ratio R Kmin Kmax for which he wants to calcu
112. iles Contents Troubleshooting Database Information Input File Formats 107 Troubleshooting This topic shows frequently asked questions and troubleshooting of ViDa Problems During ViDa Installation My CD ROM can t read the ViDa CD ViDa comes in a recordable CD media called CD R requiring a CD ROM drive with Multiread capability Most CD ROM drives are Multiread compatible however older ones may not be fast enough to run the ViDa CD If you have access to a computer with a Multiread CD ROM you can copy the files in the oetup2002 directory to 1 44 MB diskettes and then install ViDa on the original computer inserted the ViDa CD but nothing happened The ViDa CD features autorun so a few seconds after being inserted it should display a welcome window If autorun doesn t start double click on the AUTORUN EXE file in the Windows Explorer The setup program is interrupted in the beginning of the installation process Check if you have previously run the ViDa setup and canceled the installation Sometimes Windows forgets to delete temporary files in your computer especially in the c Windows and c Windows Temp directories that may cause problems in future installations To correct this problem search and delete all vida cab files that you might find in your Windows or Winnt folder Delete also the folder Msftqws pdw if from the Windows Temp folder Finally if any of the files Windows System Vb6stkit dll
113. imental data table SN eN or da dN of the Material window select the tab containing it and click Import on the Table menu To fit the eN experimental data points on the Material window to a Coffin Manson equation click Fit eN on the Tools menu Note that since there are 4 constants in the eN curve you need not only the values of 2N and de 2 but also the corresponding stress variation dS 2 Steels x Alumina Steels have in general a fatigue endurance limit the SN curve elbow associated to a 1 000 000 cycle life Alumina on the other hand do not have an endurance limit Also the Notch Sensitivity q doesn t depend on Su for Alumina while for Steels it does depend SN Method and Welded Structures Tips 45 46 47 48 49 50 The SN method is recommended only if the stress strain history at the critical point normally a notch root is elastic If the loading induces plastic deformations at the critical point then the eN method should be used instead It is recommended to use the Sequential Rainflow counter which preserves most ordering information before any SN calculations on long loading histories Fill in the Filter field above the Loading Datasheet to enable the removal of small events that cause no damage and click Sequential Rainflow on the Life menu The SN curve shown on the Material window is the Standard Estimated SN Curve which ignores the values of the endurance limit modifiers ka kb kc kd and ke
114. inder tabs The crack type will define the built in stress intensity factor KI equations that will be used in the crack growth calculation 12 For the Elliptic and Corner cracks enter the Tension and Bending factors by which the loadings of the Loading Window are multiplied and considered as Tension and or Bending Stresses applied to the specimen see the arrows in the Crack Type Drawings 13 Beside the Graph 1 option choose the field and sampling rate to be plotted in the Damage Curve 2D Crack Graph in the Main Window 14 Beside the Graph 2 option choose the field and sampling rate to be plotted in the Hysteresis Loops Elliptic Cracks Graph in the Main Window 15 Choose the calculation procedure to be used Sequential calculation or the Root Mean Square RMS approach If you chose the RMS approach jump to step 17 16 Enter the Wheeler Retard Effect exponent beta or gamma of the retard effect due to overloads enter zero in order to neglect retard effects and choose between the Wheeler corrects da dN and dc dN or the Modified Wheeler corrects deltaK retard effect corrections Choose also the percentage precision in the Retard Effect calculation Click on the Retard Effect Help button for additional information Go to step 18 17 Choose if you want to use the Simpson Integral in the RMS crack growth calculation If this option is off then the numerical integration of the da dN and dc dN equations is done with a 1 cycle
115. indows are then significantly simplified and the hidden options are set to default values which are either the simplest or the traditionally used by the fatigue design techniques To change the idiom used in ViDa among English Portuguese French German Italian or Spanish click Options on the Tools menu and select the Idiom tab You ll need to exit and restart ViDa to make the changes effective You can even add a 7th idiom if you have a Windows Resource editor to edit the Vida res file To choose between SI or English units click Options on the Tools menu and select the Units tab All the calculations and stress data in ViDa are then considered to be in MPa or ksi accordingly even though the Material database physically saves the data in SI units To add one or more rows on the Loading Datasheet highlight the number of rows to be added by dragging the mouse while pressing the left button and click Add Rows on the Edit menu The rows are added above the selection To delete one or more rows from the Loading Datasheet highlight the rows to be deleted by dragging the mouse while pressing the left button and click Delete Rows on the Edit menu To replicate a group of rows of the Loading Datasheet in order to enter repetitive blocks select the rows you want to copy by dragging the mouse on them while clicking the left button click Clone Block on the Edit menu and enter the number of times to copy this block The copied blocks are
116. inflow filtered Peak Valley history Note that the rainflow counting of the loading alters its sequencing and in consequence the calculated crack growth It is strongly recommended that the sequential rainflow counter is used instead of the traditional rainflow because sequencing is a fundamental issue in crack growth calculations see the Textbook Fatigue Design under Complex Loading 3 If you want to use a different material from the one shown in the Loading Window go to the Materials database window and choose the desired material or query for materials with certain desired properties in which case the Find Material window will appear Note that you can alter the material properties but you ll need to save the changes using the File Save command prior to any calculations It is possible to estimate properties or calculate them from experimental data please refer to the How do Use the Materials Database topic for more information After choosing the desired Material click on the File Exit command to return to the Loading Window 4 Make sure that the Extended Modeling option is chosen using the Tools Options command This option is required to let ViDa calculate bidimensional crack growth Click on Life Bidimensional Crack Growth to enter the Bidimensional Crack Growth da dN and dc dN window 5 Enter the Calculation Title in order to further identify this calculation in the Calculation Logbook window 6 You can alter the valu
117. ing ViDa to perform fatigue and fracture mechanics calculations After working on these tutorials you ll be more familiar with the necessary calculation steps and even use some of the advanced options in ViDa Contents How do Calculate Damage using the SN method How do Calculate Damage of Welded Structures How do Calculate Damage using the eN Method How do Calculate Unidimensional Crack Growth How do Calculate Bidimensional Crack Growth How do Use the Materials Database How do Handle Experimental Data Points How do Use the Equations Database How do Handle Tridimensional Stress Histories Rosette Data How do Use the Smart Calculator Useful Tips about ViDa General Tips Material Database Tips SN Method and Welded Structures Tips eN Method Tips Crack Growth Calculation Tips Other Tips 86 How do Calculate Damage using the SN method To calculate the fatigue damage and the remaining crack initiation life of a piece which critical point works under elastic stresses you can and probably should use the SN method Below there is a complete list of all steps you might need to go through to perform this calculation using ViDa Note that some of these steps can be skipped in some cases and also that some of the options are not available in the Simplified Modeling option the symbol will denote options only available in the Extended Modeling option 1 Load a Loading History or type it in
118. ion Click on the Retard Effect Help button for additional information Go to step 17 16 Choose if you want to use the Simpson Integral the RMS crack growth calculation If this option is off then the numerical integration of the da dN equation is done with a 1 cycle integration step If the Simpson Integral option is on then the user may input a value for the integration step which is a percentage of the crack size If you chose the Simpson Integral option then you can skip step 17 17 Enter the Percentage value of the Increase in Va Criterion increase percentage of the square root of the crack size for which the Stress Intensity Factor KI is recalculated used to speed up the calculations Typical values are in the 0 1 1 0 range Click on the Increase in Va Criterion Help button for additional information 18 Choose to or not to use logarithmic interpolation to iterate within each step in the numerical integration only applicable for the Sequential calculations Since the value of da dN varies within an integration step setting this option on makes the program iterate once for each integration step Slightly better accuracy is achieved with this option on 19 Choose which equations you want to use in the crack growth calculation among Paris law Elber law Walker law Modified Walker law and another da dN equation only available for the Extended Modeling option 20 Check if all options are set as desired and pre
119. late the da dN value Save As New da dN Button Adds the da dN equation present in the da dN Formula field to the Equations Database The user will be asked to enter a name for this new equation Equation Interpreter Help Button Shows just for reference a window with the equations syntax and all the material properties that can be literally used in the equations Variables Table Table containing variables that can be set by the user To set a variable just click on it and type its new value If these variables are present in the da dN or Formula then their values are used in the calculations Open Variables Button Loads a previously saved Variables Table file var containing the values of all variables from the Variables Table Save Variables Button Saves the values of the variables from the Variables Table to a Variables Table file var da dN Graph da dN curves of the material using Paris and Elber laws and a third da dN equation chosen by the user when using the Extended Modeling option Note that the value of deltaKth substantially affects the Elber law curve The graph is updated after changes in its parameters only after the Graph Redraw command is used To expand or shrink the graph just double click on it Crack Tab Retardation Options Initial Crack 1 00E 00 mm Final Value a 0 00 00 mm Final Yalue 0 criterion is ignored Width w 5 00 02 mm Typical Inf strip single ed
120. lated and the correct hysteresis loops are plotted this option counts the peaks and valleys of the strain history using the rainflow method prior to the eN curve life calculation The user can also input a strain amplitude filter in microstrains to discard the small events that cause no damage Define Loops to Plot Option Option to define a range of hysteresis loops that the user wants to plot for visualization purposes This range doesn t affect the calculations the program needs to calculate ALL the hysteresis loops in any circumstances Number of Calculation Points Resolution in number of points of each hysteresis loop for calculation accuracy purposes In general 40 points is a good choice Number of Plotting Points Resolution in number of points of each hysteresis loop for plotting purposes If you re plotting too many hysteresis loops you might have to reduce the number of plotting points for each loop This number does not affect the calculation accuracy Hysteresis Loops Help Button Shows a window with some useful information about hysteresis loops calculations Kt Stress concentration factor of the specimen relating the nominal loading history and the most stressed point Its value can also be calculated using the Calculate Kt Button Typical or the Calculate Kt Button Stored commands Calculate Kt Button Typical Command Goes to the Calculate Typical Stress Concentration Factor Kt Window where the user can calculate
121. les greater than Nf If this option is off then the elbow is ignored belb Value of the b exponent of the SN Curve after the elbow set belb 0 to ignore this option Surface Finish Surface finish of the specimen used to automatically calculate the endurance limit modifying factor ka Type of Loading Main type of loading applied to the specimen used to automatically calculate the endurance limit modifying factor kc Equivalent Diameter Specimen cross section diameter or equivalent diameter used to automatically calculate the endurance limit modifying factor kb Calculate d Equivalent Diameter Button Goes to the Calculate Effective Diameter Window where the user can calculate the effective diameter of various cross section profiles under bending This diameter is used to calculate the size factor kb used to correct the fatigue endurance limit Sf Su Ultimate strength of the current material used to automatically calculate the endurance limit modifying factor ka The default value of Su is loaded from the Materials Database but it can be changed by the user Operating Temperature Specimen operating temperature used to automatically calculate the endurance limit modifying factor kd Sf Uncorrected endurance limit of the material alternate stress below which there is no fatigue damage a Surface finish factor that modifies the endurance limit a better surface finish increases the endurance limit Size factor tha
122. mate them again by using the Edit Estimate using Nominal Values command or to replace them with measured properties Note that to change the color coding black red you need to press the space bar on the desired property field Edit Estimate using Nominal Values Command Estimates the currently null material properties To see the estimating formulas that ViDa uses click on the Estimates button All estimated properties are color coded in red Table Menu Number of Rows Save As Import MPa ksi ksi gt MPa Table Number of Rows Command Asks the user to enter the number of rows of the selected experimental data table SN eN or da dN If the users enter a smaller number of rows than the current one the corresponding rows are deleted If it s greater the extra rows are added on the bottom of the table Table Save As Command Saves the selected experimental data table SN eN or da dN as a CSV Comma Separated Values csv file Table Import Command Loads a Comma Separated Values CSV file into the selected experimental data table SN eN or da dN Note that ViDa ignores the first row of the CSV file since it assumes that the first row contains the column titles and the number and order of the columns in the file must be compatible with the respective table 2 columns for the SN or the da dN tables and 3 columns for the eN table Table MPa gt ksi Command Converts the numerical values of all the 3
123. material You can alter the material properties by clicking on the respective field and entering the new data Note that this new value will only be effective after you save it using the File Save command Values in black represent measured properties while the values in red reflect estimated properties which are less reliable To toggle the black red colors press the space bar while editing the desired field don t forget to save the changes after The following are some common procedures in the Material window After choosing the desired material and setting the property values click on File Exit to go back to the Main Window Selecting a material click on the File Open command to go to the Open Material window which shows a list of all available materials Just click on the name of the desired material to load it Searching a material with certain properties click on the File Find command to go to the Find Material window There you can search for materials by their type by choosing from steels alumina etc in the Materials list You can set any property ranges to look for just click on one of the Property lists and set the range of the chosen property on the two fields on the right in the same row Multiple criteria can be used in your search ViDa will look only for the materials that match ALL the desired property ranges You can also sort the matching materials by any property just click on one of the Order by lists and choo
124. mean components and the number of half cycles in which they were applied Example of an alt file for 2 loading events 10000 cycles of 0 to 100 to 0 and 4000 cycles of 70 to 70 to 0 expressed in stresses and duration of 3600 seconds 2 0 3600 50 50 20000 70 0 8000 3D Peak Valley files p3d ASCII files containing a sequence of peaks and valleys for all 6 tensor components XX YY ZZ XY XZ and YZ The first row contains the number of remaining rows in the file the number of events the value of the Table Option 0 for Stress values and 1 for Strain values and the values of the stress concentration factors for each of the 6 tensor components The remaining rows contain the values of the peaks and valleys for each of the tensor components XX YY ZZ XY XZ and YZ Example of a p3d file for 5 loadings expressed in stresses and stress concentration factor of 2 in the ZZ and YZ directions 5 0 1 1 2 1 1 2 100 50 200 0 0 0 50 100 0 0 0 0 200 200 200 0 0 0 50 50 40 10 15 25 0 0 0 10 15 25 110 Rosette Peak Valley files ros Files containing a sequence of strain peaks and valleys for all 3 Rosette direction components A B and C The first row contains only the number of remaining rows in the file the number of events Note that all Rosette data represent Strain values expressed in microstrains The remaining rows contain the values of the strain peaks and valleys for each of the rectangular or delta
125. meric calculator that computes any formula using the material properties and user defined variable values Some basic Mechanics of Solids equations are also embedded in the calculator and computed results can be used to multiply the loadings in the Loading Window The Smart Calculator also has direct links to the Calculate Typical Stress Concentration Factor Kt and Calculate Notch Sensitivity q for Steels and Alumina windows to compute the values of Kt q and Kf The following example will show how to convert a force history from the Loading Window that causes bending and torsion stresses on a filleted shaft into a history of equivalent stresses This conversion is fundamental since ViDa only deals with stresses or strains in its calculations not forces 1 Choose the Symbolic option and type in the Formula field the equation that will be computed in the omart Calculator Window This equation may include any variable from the Variables Table any material property or even mathematical functions click on the Equation Interpreter Help Button for more information To calculate equivalent stresses you can click on the Mises button in order to automatically type the equivalent stress equation s Kf 42 3 UKf 2 5 2 Highlight the letter s in the equation using the mouse by clicking the mouse button and dragging over the letter and press the Bending button The letter s will be replaced by the bending stress equation for a circular shaft 3
126. mitted to RBCM in Portuguese Courses 1 Advances in Fatigue Design Automation Marco A Meggiolaro and Prof Jaime Tupiassu P de Castro Ph D August 7 9 1996 PUC Rio Rio de Janeiro RJ Brasil 2 ViDa Visual Damagemeter to Automate Fatigue Design under Complex Loading Marco A Meggiolaro and Prof Jaime Tupiassu P de Castro Ph D November 12 1996 at and November 13 1996 at UConn 112
127. mula can also be edited by the user and even added to the Equations Database using the Save As New button Calculate Button Calculates the value of KI 2D stress intensity factor in a and c for the current Formula and Variables Table values The user is asked to input the stress variation deltaSigma S for which he wants to calculate the KI value Save As New Button Adds the KI 2D stress intensity factor equation present in the KI Formula fields to the Equations Database The user will be asked to enter a name for this new equation Tension Bending Pressure Factor Factor by which the loadings of the Loading Window are multiplied and considered as Tension Bending Pressure Stresses applied to the specimen see the red arrows in the Crack Type Drawings If this factor is 1 then the loading history is used as these stresses if it s zero then these stresses are not considered Use these values to combine Tension Bending and Pressure loadings Retardation Options Tab Retardation p UU No Retardation k 0 O Wheeler 1 30E 00 Retardation m 5 C Mod Wheeler 6 50E 01 Resolution C Factor Zi Zol aol ai wh E Ketardation C5 deltak Factor Zi A7 ol aol ai whm ee OEE 2 Plastic one J Effective 1 dk Z 2 Kmx Plane Stress Zi ae Le Kal Zol aal ai Zol 0 5 C Plane Strain 5 User Integration Method Graph Cycle by Cycle Sequen
128. mum Minimum 2 Edit Multiply by Constant Command Multiplies ALL the values of the Alternate and Mean or Peak Valley columns of the Loading Window by a constant value An input window will ask the user to enter this constant value Edit Add Constant Command Adds a constant value to ALL the values of the Alternate and Mean or Peak Valley columns of the Loading Window An input window will ask the user to enter this constant value View Menu Toolbars Standard Edit Material Status Bar Refresh Logbook Options View Toolbars Standard Command Shows hides the Standard toolbar View Toolbars Edit Command Shows hides the Edit toolbar View Toolbars Material Command Shows hides the Material toolbar View Status Bar Command Shows hides the Status Bar View Refresh Command Refreshes the active window redrawing its graphs tables and other components View Logbook Command 18 Shows the Calculation Logbook window which keeps track of all previous calculations storing the total damage and residual life of the specimen for each SN IIW and eN calculation or the average da dN and the total crack growth for each crack growth calculation By filling out the Calculation Title field in the calculation windows it is possible to easily compare the results of different calculations in the Calculation Logbook window This command has the same functionality as the Life Logbook command View Options Command Sho
129. n Window then the residual life is not added to the Calculation Logbook since it cannot be calculated This window is a very useful tool to compare similar calculations with different option settings from the life crack growth calculation windows The tables can also be saved or loaded from a file as a log file or printed by the user using the menu commands of the Main Window when the Logbook window is focused IB Logbook LIBI XI Iw ECCS 20 eM Method Print Title Loffin Manson Morrow EL Morrow EP Hemo 00 57 51 DAHAGI 5 7039E 06 6 7173E 06 1 5igmaf 8 0 ep ia BLOCE S B 1 75E 05 B 1 49E 05 9 54 04 Kt 2 00E 00 Ke Ks DAMAGI 1 084 7E 05 1 2825E 05 2 1712E 05 Sigmaf 8 96E 027ep BLOCKS B 9 22E 04 B 7 80E 04 B 4 61E 04 Kt 2 00E 00 Ke Ks DAMAGI 4 1271E 06 4 7448 6 5616E 06 Sigmaf 8 96E 02 ep BLOCE 5S B z2 4 E 05 B 2 11E 05 1 52 05 Et 1 50E 00 Ke Ks DAMAGI 9803 1 9497E 07 1 5145E 06 Sigmaf 8 96E 02 ep BLOCKS B 1 25E 06 B 1 01E 06 B 6 60E 05 Kt 1 50E 0 K e K s t DAMAGI 1 084 7E 5 1 2825E 05 2 1712E 05 Sigmaf 8 96E 02 ep BLOCE 5S B 9 2 E 04 B 7 80E 04 B 4 61E 04 2 00E O K e K s t DAMAGI 1 3798E 05 1 6112E 05 2 f422E 05 Sigmaf 8 96E 027ep BLOCKS B 7 25E 04 B 6 71E 04 B 3 Bb5E 04 Et 2 10E 00 Ke Ks 00 53 03 00 55 25 00 55 38 00 55 49 00 55 55 gt Table Tables that store the total damage
130. n only if the Show Hysteresis Loops Graph option is checked on the Options window 15 File Menu New Open Close Save Save As Save All Print Print Preview Export Recent Files Exit File New Command Creates a new Loading Window for entering a new loading history File Open Command Opens a loading file It can be a file in which the loading is described by a series of alternate and mean components and by the number of half cycles they act alt a file in which the loading is described by a series of peaks and valleys pic a comma separated value file csv or an Excel file xls First a Standard Load File window asks you to choose the CSV or Excel file and then the Open File window asks you to choose which data field you want to load to the Loading Window output files from the Kyowa RHS 500A histogrammer 1 A Tridimensional Peak Valley p3d or Rosette Peak Valley ros file In this case ViDa automatically goes to the Equivalent Stress Window and loads the chosen file Calculation Logbook log files containing the results of previous life calculations These files are loaded to the Calculation Logbook Window ADINA output files port loaded as a Peak Valley history of the chosen node File Close Command Closes the current window lt is the same as clicking on the close button on the title bar of each window the X mark on the top right of any window
131. n purposes When considering strain concentration factors on the hysteresis loops two main theories are commonly used Linear theory which considers Ke Kt strain concentration Ke is equal to Kt and Neuber theory which uses 2 ViDa lets you choose any of these theories on the eN method window The eN method window lets you automatically correct the eN curve elastic exponent b using Sf ka kb kc kd ke Sf the SN curve approach introduce an elbow with the Consider SN Curve Elbow option and even set a value of the eN curve slope after this elbow by setting the SN curve s exponent belb oince all plastic events induce memory it is strongly recommended that the eN method be applied to the original sequence of the loading stresses You should not rainflow count the loading before eN calculations it is recommended that you select the option to rainflow count the calculated strains on the eN method window instead Rainflow counting the calculated strains is the recommended method for eN calculations available on the eN method window Rainflow counting the stress history before drawing the hysteresis loops alters the loading order ending up with wrong hysteresis loops and wrong calculated damage When Rainflow counting the calculated strains on the eN method window the hysteresis loops are calculated following the original loading order the resulting calculated strain history is Rainflow counted and finally the eN life
132. n you use the Rainflow or Sequential Rainflow commands If this option is turned off the resulting Alternate Mean component history is shown on the same window replacing the original Peak Valley data in this case ViDa asks if you want to save the Peak Valley history before replacing it Open Rainflow of Calculated Strains in New Window Option ViDa creates a new Loading Window when you choose the Rainflow of Calculated Strains option on the eN Method window If this option is turned off the resulting Alternate Mean strain history is shown on the same window replacing the original data in this case ViDa asks if you want to save the original history before replacing it Show Tips at Startup Option Lets the program show the Tip of the Day window every time you run ViDa 80 Modeling Tab Database File Locations E icr Ho Fit a Extended 9 immi B U Eurasia lap PECORE Simplified Sefaz Lets the user choose between Simplified or Extended modeling The SN IIW eN and da dN windows will be significantly simplified if the Simplified Modeling is chosen presenting much less options for the user These hidden options are set to default values that reflect either the simplest or the traditional fatigue design techniques Thus the Simplified option is recommended for beginners whereas the full windows are for experts Note also that the Bidimensional Crack Growth window is not availabl
133. nd enter the appropriate values for these parameters of the SN curve Note that in general you don t need to change these values since they re automatically loaded from the Materials Database and corrected when you alter any ka kb kc kd or ke values You can also calculate the values of b and c or retrieve them from the Materials Database by using the Calculate b c button If you want you can right click on the SN curve graph and choose Redraw to see the changes in it 9 Enter the value of the b exponent after the SN curve elbow belb If this value is set to zero then the SN curve is horizontal after the elbow if any otherwise you ll obtain a SN curve with 2 different slopes You can also right click on the SN curve graph and choose Redraw to see the changes in it 87 10 Enter the value of the End of life at damage field This is the total damage value that characterizes failure of the specimen The Palmgreen Miner rule suggests a total damage value of 1 for the end of life but any other value can be chosen by the user 11 Enter the name and parameters of a user defined damage curve that will be used in the calculations in addition to the Goodman Gerber and Soderberg curves These 4 curves can be visualized in the SaSm graph for any reference life by right clicking on it and choosing the Define Life for SaSm command 12 Choose if you want i to Consider the SN Curve Elbow ii to Use the Stress Concentration Factor
134. nglish Portuguese French German Italian Spanish Note that once you change the idiom you need to exit and restart the ViDa program in order to make the changes effective 83 Multimedia Window Window with links to the Textbook Fatigue Design under Complex Loading Published Papers and video animations The Slide Show and ViDa Papers buttons go to the PowerPoint Presentation Viewer where you can choose among the book Fatigue Design under Complex Loadings or the Published Papers pertaining to ViDa The Chain button shows a small animation about the principles of structural integrity evaluation zs L E n in Tip of the Day Window Show tips on working with ViDa at the startup You can see more tips by pressing the Next Tip button or you can view all tips using the Show button If you don t want to see the Tip of the Day window every time you run ViDa just disable the Show Tips at Startup option and press OK 84 Tip of the Day Did know The Sequential Ramflow variation of the Hainflaw that partially retains the loading order Chow which very useful both with the eM method is and with the crack growth calculations which are very sensitive to the loading order perform it on a Feak alley history click Sequential Fiainflew the Life menu Show Tips at Startup 85 CHAPTER 4 ViDa Tutorials This chapter presents some detailed tutorials on us
135. nsitive to the mean component of the applied stresses because a large amount of residual stresses has already been introduced by the welding process which is already taken into account by the Weld Joint Class The value of the Weld Joint Class defined by the International Institute of Welding IIW is actually the fatigue strength in MPa of the weld joint associated with a life of at least 2 000 000 cycles within a 97 reliability eN Method Tips 71 72 73 74 75 76 TT 78 To achieve reliable results by the eN strain life method it is highly recommended to calculate the correct elastoplastic hysteresis loops which act at the critical notch root To enable corrected hysteresis loops calculations click eN Method on the Life menu and check both the Calculate Hysteresis Loops and Loop Corrections options To calculate hysteresis loops in the eN calculations check Calculate Hysteresis Loops on the eN method window Since not calculating the loops in general leads to unrealistic and probably non conservative calculated strains this option combined with the Loop Corrections option is highly recommended The eN curve of any material should converge to its SN curve for high cycle lives where elastic deformations dominate The eN method window lets you consider an elbow on the elastic component of the eN curve derived from the SN s fatigue endurance limit and also plots together both SN and eN curves for compariso
136. nsitivity factor which is used to calculate the fatigue or effective stress concentration factor Kf 1 q Kt 1 Calculate Kt Button Typical Command Goes to the Calculate Typical Stress Concentration Factor Kt Window where the user can calculate the value of Kt for Notched Filleted Bars or Shafts of any dimensions Calculate Kt Button Stored Command Goes to the Smart Calculator window where the user can calculate the value of Kt using the equations from the Kt Equations Database or any other equation defined by the user Calculate q Notch Sensitivity Button Goes to the Calculate Notch Sensitivity q for Steels and Alumina Window where the user can calculate q for steels or alumina given the notch radius and Su OK Button Calculates the damage using the SN Method for the Loading Window loadings using the material properties and the chosen options and goes back to the Main Window Cancel Button Cancels the SN Method calculation and goes back to the Main Window 42 Calculate Life SN Simplified Window Calculates the damage and remaining life using the SN Method and the loading history from the Main Window The SN method is recommended only if the stress strain history at the critical point normally a notch root is elastic The user can input the specimen characteristics such as surface finish or equivalent diameter to determine the values of ka kb kc kd and ke alter the material SN curve equation calculate and
137. nter a value for the amplitude Filter optional and then click Life Rainflow The Loading Window will then contain the Rainflow filtered Peak Valley history Note that the rainflow counting of the loading alters its sequencing and in consequence the calculated crack growth is strongly recommended that the sequential rainflow counter is used instead of the traditional rainflow because sequencing is a fundamental issue in crack growth calculations see the Textbook Fatigue Design under Complex Loading 3 If you want to use a different material from the one shown the Loading Window go to the Materials database window and choose the desired material or query for materials with certain desired properties in which case the Find Material window will appear Note that you can alter the material properties but you ll need to save the changes using the File Save command prior to any calculations It is possible to estimate properties or calculate them from experimental data please refer to the How do Use the Materials Database topic for more information After choosing the desired Material click on the File Exit command to return to the Loading Window 4 Click on Life Crack Growth to enter the Crack Growth da dN window 5 Enter the Calculation Title in order to further identify this calculation in the Calculation Logbook window 6 You can alter the values of deltaKth Klc A and m from Paris law A and m from Elber law and
138. nto the Loading Datasheet click Open on the File menu and select the files of type Kyowa Files 1 To import porthole files port from the ADINA Finite Element software into the Loading Datasheet click Open on the File menu and select the files of type ADINA Porthole Files port por To expand or shrink any graph in ViDa double click on it with the mouse To view the coordinates of a point in any graph click on it with the mouse and its coordinates will appear in the Main Window status bar To import CSV files csv to the Hysteresis Loops Elliptic Cracks graph right click on the graph with the mouse and select Import CSV File You ll have the option to select 2 columns from the file to be plotted against each other To save the Hysteresis Loops Elliptic Cracks graph values as a CSV file csv right click on the graph with the mouse and select Save As CSV File You can later Import this CSV file to review old calculation plots To save most graphs in ViDa as a CSV file csv right click on it with the mouse and select Save As CSV File The first row in the saved file will contain the legend titles of each set in the graph and the following rows will contain the respective data for each set To print any graph in ViDa change its axes scale useful to keep the aspect ratio of plotted elliptical cracks fronts or even export its values as a CSV file csv right click on it with the mouse and select the appro
139. o the IIW window for damage calculation of welded structures using the current Loading Window values Note that the material properties will not be used in this calculation since it is sufficient to know the class of the weld Life eN Method Command Goes to the Calculate Life eN window for damage calculation using the current material and Loading Window load values Life da JdN Method Command Goes to the da dN Method window for unidimensional crack growth calculation using the current material and Loading Window values Life Bidimensional Crack Growth Command Goes to the Bidimensional Crack Growth window for elliptical crack growth calculation using the current material and Loading Window values Life Logbook Command Shows the Calculation Logbook window which keeps track of all previous calculations storing the total damage and residual life of the specimen for each SN IIW and eN calculation or the average da dN and the total crack growth for each crack growth calculation By filling out the Calculation Title field in the calculation windows it is possible to easily compare the results of different calculations in the Calculation Logbook window Tools Menu Equivalent Stress Stress Concentration Factor Kt Notch Sensitivity q Smart Calculator Options Tools Equivalent Stress Command Goes to the Rosette and 3D Equivalent Stress window for converting 3D loadings or Rosette measurements into 1D components u
140. onal and then click Life Rainflow The Loading Window will then contain the Rainflow filtered Peak Valley history Note that the rainflow counting of the loading alters its sequencing and in consequence the calculated damage t is strongly recommended that the eN method be applied to the original sequence of the loading if it consists of stresses In the Extended Modeling option you can choose to rainflow count the calculated strains which is the recommended method to guaranty the accuracy of the calculations see the Textbook Fatigue Design under Complex Loading 3 If you want to use a different material from the one shown in the Loading Window go to the Materials database window and choose the desired material or query for materials with certain desired properties in which case the Find Material window will appear Note that you can alter the material properties but you ll need to save the changes using the File Save command prior to any calculations It is possible to estimate properties or calculate them from experimental data please refer to the How do Use the Materials Database topic for more information After choosing the desired Material click on the File Exit command to return to the Loading Window 4 Click on Life eN Method to enter the Calculate Life eN window 5 Enter the Calculation Title in order to further identify this calculation in the Calculation Logbook window 6 Choose the Surface Finish Type of Loa
141. or Windows St6unst exe has a size of 0 bytes delete them Then retry installing ViDa received an access violation error message Access violation errors occur when you try to install files that are already running in your computer Just choose Ignore and then confirm by pressing Yes This message is very common with the mfc40 dll file To prevent these messages it is recommended to close all open applications before installing or even restart your computer before installation received a path file access error message at the end of the installation Just click Retry and the installation will proceed This error may occur if you previously tried to install ViDa and aborted the installation process To avoid this message search and delete all vida cab files that you might find in your hard disk before installation When I run ViDa for the first time receive a message that some file is missing The ViDa CD contains copies of all installed files in the AllFiles directory Copy the missing file to the hard disk and retry running ViDa You might need to uncheck the Read Only attribute of the copied file in your hard disk If the missing file is nslock15vb6 ocx you ll also need to register it Copy this file from the AllFiles directory in the CD to your Windows System directory Then register the control by clicking on Start menu selecting Run and typing regsvr32 c windows system nslock15vb6 0cx If yo
142. previously defined in the Filter text box on the Loading Window Edit Check Peaks Valleys Command Checks the coherence of a peak valley history from the Loading Window eliminating the incoherent events Edit Convert MPa gt ksi Command Converts ALL the values of the Alternate and Mean or Peak Valley columns of the Loading Window from MPa mega Pascals to kpsi kilo pounds per square inch by multiplying them by 0 145 Note that this command only changes numerically the values of the Loading Window To use English instead of SI units for the whole program use the Tools Options command Edit Convert ksi gt MPa Command Converts ALL the values of the Alternate and Mean or Peak Valley columns of the Loading Window from kpsi kilo pounds per square inch to MPa mega Pascals by dividing them by 0 145 Note that this command only changes numerically the values of the Loading Window To use SI instead of English units for the whole program use the Tools Options command Edit Convert Alt Med gt Max Min Command Converts ALL the values of the Alternate and Mean columns of the Loading Window to a sequence of Maximum and Minimum values where Alternate Maximum Minimum 2 and Mean Maximum Minimum 2 Edit Convert Max Min gt Alt Med Command Converts ALL the values of a Maximum and Minimum history of the Loading Window to a sequence of Alternate and Mean components where Alternate Maximum Minimum 2 and Mean Maxi
143. priate command To redraw the Hysteresis Loops graph using thin lines right click on it with the mouse and select Change Curve Thickness Making the curves thinner helps in visualizing graphs with too many lines To toggle between Log Log or Linear representations of any SN eN and da dN graphs right click the respective graph with the mouse and choose the desired option Material Database Tips 33 34 ViDa has a complete Material Database with stress strain curves SN eN and da dN data and many other properties of over 400 materials This database can be expanded by the user with no storage limits and all the materials can be searched by user defined criteria To enter the database click Data Material If you change properties in the Material Database you need to click Save on the File menu to be able to use these changes in the life calculations To create a new material click Save As New on the File menu 101 35 36 37 38 39 40 41 42 43 44 To search for materials by their type steels alumina etc by any property ranges e g steels with Su between 600 and 800 MPa or any combinations of properties click Search on the File menu of the Material window You can also sort the matching materials by any property ViDa has a read only table where you can browse through all available materials and property values and easily group or sort them by any property To access the Browser Table yo
144. ption or the X Y Z and T registers for the Numeric option Kt Kf Button Goes to the Calculate Typical Stress Concentration Factor Kt Window where the user can calculate the value of Kt or Kf for Notched Filleted Bars or Shafts of any dimensions After pressing OK the program returns to the Smart Calculator Window carrying the Kt or Kf value and typing it in the Formula field on the cursor position if some letters are highlighted then they re deleted and replaced by the value q Button Goes to the Calculate Notch Sensitivity q for Steels and Alumina Window where the user can calculate q for steels or alumina given the notch radius and Su After pressing OK the program returns to the Smart Calculator Window carrying the q value and typing it in the Formula field on the cursor position if some letters are highlighted then they re deleted and replaced by the q value Normal Bending Torsion Shear Button Writes the basic formula of Normal or Bending or Torsion or Shear stress in the Formula field on the cursor position if some letters are highlighted then they re deleted and replaced by the formula Mises Tresca Button Writes the basic formula of the Mises or Tresca criterion in the Formula field on the cursor position if some letters are highlighted then they re deleted and replaced by the formula Open Kt KI da dN Button Shows a list of all available equations to be loaded Just click on the name of t
145. quivalent Peaks and Valleys The values are plotted only after the calculation New Button Clears the Tridimensional Table Open Command Loads a Peak Valley file pic into one or more of the columns of the Tridimensional Table for XX YY ZZ XY XZ or YZ or Rosette Table for A B or C Just select any cells from the columns where you want to load the history and press the Open Button You can also load a Tridimensional Peak Valley file file extension p3d which contains all the Tridimensional Table columns XX YY ZZ XY XZ and YZ You can also load a Rosette Peak Valley file file extension ros which contains all the Rosette Table columns A B and C see the Calculate Rosette Equivalent Stress Window Save Button Saves the Tridimensional Table as a Tridimensional Peak Valley file file extension p3d which contains all the Tridimensional Table columns XX YY ZZ XY XZ and YZ In the Calculate Rosette Equivalent Stress tab this command saves the Rosette Table as a Rosette Peak Valley file ros instead Edit Button Shows a Pop up menu with commands to edit the Tridimensional Table For more information on the Edit commands se the Edit menu in the Main Window Calculate Button Shows a Pop up menu with the following commands Mises Tresca Maximum Principal Stress Maximum Absolute Principal Stress Calculate Button Mises Command Calculates an equivalent Peak Valley history from the Tridimensional Table
146. r is then asked to choose which field he wants to load to the Loading Window and allows him to enter an optional conversion factor to multiply these values You can also Amplitude Filter these converted values and even choose to load just a histogram of the file useful for very large loading histories Sequence Black Cycle Position mm Conversion Factor F Filter Do X Histogram Alternate Interval Mean Interval Reverse Order Cancel Fields List Fields from the chosen comma separated value CSV or Excel xls file Just click on the desired field and press OK to load it in the Loading Window Conversion Factor Optional conversion factor to multiply the loaded values For instance if your CSV field contains forces and you know the cross sectional area you can type its inverse value in the Conversion Factor and then obtain stresses in your Loading Window be careful with the units Filter Optional amplitude filter that can be used to filter the loading history Useful for files with long histories Histogram Option Option to load just a histogram of the file being read Useful for files with long histories Alternate Interval Discretization interval used on the Histogram of the Alternate components of the loading history being read Mean Interval Discretization interval used on the Histogram of the Mean components of the loading history being read If this option is checked a bi
147. r of cycles above which there is no fatigue damage and even a reliability factor for the calculations This window also contains the weld joint class values for many typical weld joints Just click on the drawing of the desired weld joint to load its class and description After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations Calculation title Exponent m 1 rj Fatigue limit M cycles 5 00E 06 End of life damage Reliability 144 x Consider 5M Curve Elbow m elb 0 Class zi HPa k Type 18 transverse load carrying fillet welded lap joint toe Failure stress calculated on basis that loaded plates are same width as cover plates v X Cancel Calculation Title Title of the calculation that is about to be performed This is an optional field useful to identify and compare results from different calculations in the Calculation Logbook Window Exponent m Exponent m from the International Institute of Welding IIW equation N cycles 2 000 000 weld class applied stress m The default value of m is 3 0 Fatigue Limit N Number of cycles above which there is no fatigue damage for the Weld Joint The default value of N is 5 000 000 Initial Damage Initial damage value before the loading history using the Palmgreen Miner rule End Life at Damage Total damage value that characterizes failure of the weld The Palmgreen
148. rdation Options Retardation Wu Mo Retardation k ive ade o 2 Retardation O Wheeler 3 E 00 Retardation M ion B 2 Wheeler 6 50E 01 ASSUME C5 Factor wh lay Retardation C deltak Factor Zi 7 ol aol ai whm ee EE 5 Plastic one 2 Effective 1 dK 7 2 Plane Stress Z4 m Kal Zol aal ai Zol 0 5 C Plane Strain 5 User Integration Method Cycle by Cycle Sequential Kms No Retardation Eos EGER LOE Retardation Effect Option of retardation effects due to overloads Retardation Effect Help Button Shows a window with some information about the Retardation Effect models used by ViDa No Retardation Option Option not to consider crack retardation effects Wheeler Option Option to use the Wheeler retard effect correction Here da dN is multiplied by the factor PZi PZol aol ai wh where wh is the Wheeler exponent PZol and aol are the plastic zone and crack sizes on the overload and PZi and ai are the current plastic zone and crack sizes Modified Wheeler Option Option to use the Modified Wheeler retard effect correction Here deltaK is multiplied by the factor PZi PZol aol ai whm where whm is the Modified Wheeler exponent PZol and aol are the plastic zone and crack sizes on the overload and PZi and ai are the current plastic zone and crack sizes da
149. rial is a steel or an aluminum Press the OK button to go back to the previous window bringing and updating the calculated values of Kt and q or Cancel to return without carrying these values Circ Hole Hect Plates Elliptic Hole Diamond Hectang Hole Multiple Holes Hotched Cylinders Tubes Filleted Cyl Hotched Fill Plates Lic Hole Inf Plates t T V 2r F H C t D 2ry 6 H G D 2hYt 6 H G D hYt 6 F h h P O D 2hyt H G D 2hy t 6 20 mm h 3 mm 3 19E 00 mm mm 1 7 67E 01 5 u 441 2 68 00 Specimen Drawing Drawing of the available specimen types for that chosen specimen group Just click on the desired drawing to see its Kt graph and calculate the values of Kt q and Kf Kt Graph Graph showing the Kt values for a specific specimen type as a function of its dimensions Variables Values of the dimensions of the specimen drawings used to calculate Kt Radius r Value of r on the specimen drawings used to calculate Kt q and Kf Su Ultimate strength of the material used to calculate q The default value is loaded from the Materials Database but it can be changed by the user Calculated Kt q and Kf Calculated values of Kt stress concentration factor q notch sensitivity and Kf fatigue or effective stress concentration factor Kf 1 q Kt 1 These values are automatically calculated for the chosen specimen drawing using 45 the variables values r and S
150. rom the Paris equation da dN A deltaK m The default value of m is loaded from the Materials Database but it can be changed by the user Calculate Paris Button Materials Database Values Command Loads the values of the A and m coefficients of the Paris da dN equation da dN A deltaK m from the Materials Database directly into the current window Calculate Paris Button Fitted from Experimental Points Command Loads the values of the and m coefficients of the Paris da dN equation da dN A deltaK m from the Experimental Points tab in the Materials Database directly into the current window Calculate Paris Button Rolfe Barson Command Calculates the A and m coefficients of the Paris da dN equation da dN A deltaK m from Rolfe Barson s estimates that depend only on the steel microstructure Elber Option Option that let the user choose the Elber equation da dN A deltaK deltaKth m among the da dN equations he wants to use in the crack growth calculation Checking all options makes the program calculate crack growth independently using all da dN equations but the calculation takes longer A AEI Coefficient A from the Elber equation da dN A deltaK deltaKth m The default value of A is loaded from the Materials Database but it can be changed by the user m Exponent m from the Elber equation da dN A deltaK deltaKth m The default value of m is loaded from the Materials Database but it can be changed by the user
151. s Choose also the Loop Corrections option in order to make the program correct the wrong hysteresis loops that classical theory would predict You can also choose to plot the Cyclic Stress Strain curve together with the loops in order to better visualize the importance of these loop corrections Note that if the Show Hysteresis Loops Graph option from the Options window is not checked the loops are not plotted on the screen but they are calculated and corrected anyway 13 Once the Calculate Hysteresis Loops option is chosen you can choose to calculate the Rainflow of the calculated strains which is the recommended method instead of performing Rainflow before drawing the hysteresis loops If you use step 2 and calculate Rainflow before drawing the loops instead of using the Rainflow of Calculated Strains option you ll end up with different hysteresis loops than the actual ones therefore you will calculate a wrong damage Once you choose to calculate the Rainflow of the calculated strains you can also choose i an amplitude filter in microstrains ii to specify the range of hysteresis loops you want to plot iii the accuracy of the calculations and iv the plotting resolution 14 Enter the value of the Stress Concentration Factor Kt This value can also be calculated using the Calculate Kt button Typical which goes to the Calculate Typical Stress Concentration Factor window and calculates Kt given a desired geometry or the Cal
152. s or stresses in this average direction using the Direction field and the Calculate Rectangular or Delta Projected Strain or Calculate Rectangular or Delta Projected Stress commands Equivalent Peak Valley Table Peak Valley table containing the output from equivalent loading history calculations The components of the Rosette table are combined and the resulting history is shown here Transfer Button Copies the Equivalent Peak Valley Table values to a new Loading Window on the Main Window Exit Button Exits the Calculate Rosette Equivalent Stress Window and goes back to the Main Window without transferring the Equivalent Peak Valley Table 77 Smart Calculator Window Alphanumeric and RPN calculator that computes any formula using the material properties and user defined variables Some basic Mechanics of Solids equations are also embedded in the calculator and computed results can be used to multiply the loadings in the Loading Window The Smart Calculator also has direct links to the Calculate Stress Concentration Factor Kt window to compute and import the values of Kt and Kf 1 q Kt 1 into the calculations and you can load any equation from the Kt and da dN Equations Database Numeric Option Sets the Smart Calculator as a RPN Reversed Polish Notation numeric calculator with 4 registers X Y Z and T Numeric Symbolic da d dk Paris Elber dE da dM Pars Elber al CE T al coe m
153. se between Descendent to sort from the highest to the lowest values or Ascendant sorting order Browsing all material properties click on the File Browse command to go to the Browse Material window There you can see all properties of all materials on a single table You can customize the table layout change the order of the columns and the materials are automatically sorted by the property on the first column of the table Double click on the name of the desired material to load it to the Material Window Altering material properties just type the new value of the property and click on the File Save command Before saving you can also press the space bar on the value in order to toggle between black or red coding colors black for measured more reliable properties and red for estimated properties Note that you need to save the changes for them to become effective and available for further calculations Only after saving the properties the graphs in the window are updated Creating a new material click on the Edit Clear All Properties command to clear all properties Now enter the name of the new material which must be different from all other ones since all materials must have an unique name in the database You can also enter some comments in the Name field such as the Brinnell hardness in order to tell apart materials with the same name Be sure to choose the material type steel aluminum etc from the Material list and enter the
154. sing Mises or Tresca criteria Tools Stress Concentration Factor Kt Command Goes to the Calculate Stress Concentration Factor Kt window where Kt and also the notch sensitivity q for steels or alumina can be calculated for typical notched and filleted bars and shafts given its dimensions Tools Notch Sensitivity q Command Goes to the Calculate Notch Sensitivity q for Steels and Alumina window where the notch sensitivity can be calculated for steels or alumina given Su and the notch radius Tools Smart Calculator Command Shows the Smart Calculator window where the user can use an alphanumeric calculator to compute any formula using the material properties and user defined variables Some basic Mechanics of Solids equations are also embedded in the calculator and computed results can be used to multiply the loadings in the Loading Window Tools Options Command Shows the Options window where the user can set the ViDa general options regarding Editing of the Loading histories the Modeling option used for all calculations Extended or Simplified the Units used SI or English and the idiom used on the user interface among English Portuguese French German Italian Spanish and more Help Menu Contents Search For Help On Multimedia Register Tip of the Day About ViDa Help Contents Command Loads the ViDa Help file and shows its Contents Help Search For Help On Command Loads the ViD
155. splayed in the Formula field You can directly alter the formula for the chosen equation in the Formula field click on the button for information on the available functions from the equation interpreter Note that the next time you call the Crack Growth da dN window this formula will be loaded again from the equations database meaning that directly altering the formula will only affect the current calculation In order to save an edited formula as a new equation you should use the Save As New button or go to the KI Equations Database Window 13 Alter the values from the Variables Table in order to adjust the parameters if any besides a and w of the chosen KI equation Just click on the desired variable and enter its new value you can also load a previously saved Variables file var which contains all values from the Variables Table You can also calculate the Kl value for a specific stress variation deltaSigma by clicking on the Calculate button 14 Choose the calculation procedure to be used Sequential calculation or the Root Mean Square RMS approach If you chose the RMS approach jump to step 16 15 Enter the Wheeler Retard Effect exponent beta or gamma of the retard effect due to overloads enter zero in order to neglect retard effects and choose between the Wheeler corrects da dN or the Modified Wheeler corrects deltaK retard effect corrections Choose also the percentage precision in the Retard Effect calculat
156. square root of the crack size criterion OK Button Calculates crack growth using the da dN Method for the Loading Window loadings using the material properties and the chosen options and goes back to the Main Window Cancel Button Cancels the crack growth calculation and goes back to the Main Window 61 Typical da dN Curves Window Lets the user choose from typical da dN equations To select the desired equation just click on the respective figure a Typical Crack Growth Equations Walker Walker Iber 3 Param R0 avi Feddersen Hall 4 Param HU lt nddle 4 Param 4 Param Plane Stress Plane Strain 62 Typical Stress Intensity Factor Window Lets the user choose from typical stress intensity factor equations including KIII and 2D for bidimensional crack growth equations To select the desired equation just click on the desired specimen Kl Equations Infinite Plates 1 Infinite Plates 2 5emi Inf Plates 1 Tubes Cylinders Oblique Cracks Suis Strips 2 e OC u t B t o 63 Kil and Kill Equations Semr Inf Z thers KIII Stups Semi Inf Others 5 1 5trps 2 H Ow t 3 2c m rer e H OT t 32 Crack Growth da dN Simplified Window Calculates unidimensional crack growth using the da dN Method and the loading history from the Main Window The user can inp
157. ss the OK Button The total crack growth and average da dN will be calculated for all the chosen da dN equations and shown in the Loading Window 93 How do Calculate Bidimensional Crack Growth Surface cracks grow bidimensionally i e both sideways and in depth Certainly we cannot rely in pure unidimensional crack growth calculations ViDa handles these bidimensional cracks and calculates crack growth in both directions considering the changes in crack shape using any da dN equation specified by the user recognizing retardation and crack arrest effects The cracks are assumed elliptical in shape with semi axis a and c The corner crack is assumed to be a quart ellipsis the surface crack a semi ellipsis and the internal crack a full ellipsis The cracks can change the a c ratio during their propagation but remain elliptical 1 Load a Loading History or type it in the Loading Window 2 If the loading is a sequential history you might want first to Check or Filter it Unless your loading history comes from an histogrammer as a set of Alternate Mean no of half cycle components thus not keeping order or sequencing information it is recommended to use a rainflow counter Make sure that the history in the Loading Window is expressed as a Peak Valley sequence by clicking on Peak Valley in the Sequencing Option enter a value for the amplitude Filter optional and then click Life Rainflow The Loading Window will then contain the Ra
158. stimate how long it would take to end the life of the specimen provided that the same loading rates would continue to be applied The Sequential Rainflow is a variation of the Rainflow that partially retains the loading order which is very useful both with the eN method and with the crack growth calculations which are very sensitive to the loading order To perform it on a Peak Valley history click Sequential Rainflow on the Life menu Be careful when using the amplitude filter above the Loading Datasheet since greater filter values can significantly decrease the computational effort but also can lead to non conservative damage calculations To use it type in a value different than zero and click Filter Edit menu Rainflow or Sequential Rainflow Life menu some keyboard commands for editing the Loading Datasheet Enter move down one cell Arrows move along cells Ctrl Arrows jumps to the beginning or end of table Shift Arrows selects group of cells for copying etc Ctrl dragging the mouse copies current cell value to all your selection To import a CSV file csv to the Loading Datasheet click Open on the File menu and choose which column to load ViDa automatically eliminates points that are not peaks nor valleys You can also specify a conversion factor to multiply the loaded values and even use a Racetrack Filter to limit the size of the history To import output files from the Kyowa RHS 500A histogrammer i
159. t can be set by the user To set a variable just click on it and type its new value If these variables are present in the da dN or Formula then their values are used in the calculations Open Variables Button Loads a previously saved Variables Table file var containing the values of all variables from the Variables Table Save Variables Button Saves the values of the variables from the Variables Table to a Variables Table file var da dN Graph da dN curves of the material using Paris and Elber laws and a third da dN equation chosen by the user when using the Extended Modeling option Note that the value of deltaKth substantially affects the Elber law curve The graph is updated after changes in its parameters only after the Graph Redraw command is used To expand or shrink the graph just double click on it Crack Tab Initial Crack 1 00E 00 mm FinalValue a 0 00E 00 mm t plate semi elliptic surface crack Tensio Initial Crack 2 00E 00 mm Final Value c 0 00 00 mm Final Value l criterion is ignored Width w 5 00 02 mm Rect plate semi ellipic surface crack Tension amp Bending Zw t H Cw t 3 Tension Factor 1 Bending Factor lo 1 0 02 1 00 00 SUE 02 L f 500E 0 5 00 02 2 00E 00 200E 01 11 00 03 me 1 0000 x 100E 00 _ 1 01 00 01__ 3 50 00 5 29E 06 7 58E 01 2 5 00
160. t modifies the endurance limit smaller specimens have greater endurance limit than larger ones Loading factor that modifies the endurance limit depends on the main type of loading applied to the specimen Temperature factor that modifies the endurance limit greater temperatures bring down Sf e Miscellaneous factors that modify the endurance limit e g corrosion Be careful not to include the stress concentration factor Kt or Kf in the value of ke since Kt and Kf are already taken care of in the stress calculation SN Graph SN curve of the material considering the endurance limit modifiers ka kb kc kd and ke The graph is updated after changes in its parameters only when the Graph Redraw command is used To expand or shrink the graph just double click on it 40 Damage Curve Tab Calculation title User Damage Curve Name 5 bed Diazram Alternate Stress Exp 1 50 00 8 Hean Stress Exp 1 50E 00 Ref Mean Strength 441E 02 MPa Sm lt lj Goodman hi x Use Kt in 5mean Plot Soderberg Initial damage 00 400 200 End of life damage Sm MPa x Consider Residual 5tresses Initial Hes Str o f Linear Theory Ke Kt Calculation Pts Initial 4 Neuber System Ke Ks Kt 2 Plotting Pts 20 Final 100000 2 00 7 BE Cancel User Damage Curve Curve relating combinations of alternate Sa and mean stresses Sm that lead to
161. table To highlight them just drag the mouse while pressing the left button Edit Insert Rows Command Inserts one or more rows to the Loading Window The number of rows to be added is defined by the highlighted cells in the table To highlight them just drag the mouse while pressing the left button Edit Replicate Block Command Copies a group of rows of the Loading Window as many times as desired Use this command to enter repetitive blocks in your history First select the rows you want to copy by dragging the mouse on them while clicking the left button Then click on this command and enter the number of times you want to copy this block The copied blocks will be inserted below the last selected row Edit Fill Cells Command Sets the value of a group of cells of the Loading Window First select the rows you want to set by dragging the mouse on them while clicking the left button Then click on this command and enter the value you want to set for them Edit Reset Command Deletes all rows and data from the current Loading Window 17 Edit Number of Rows Command Asks the user to enter the number of rows of the current Loading Window If the users enter a smaller number of rows than the current one the corresponding rows are deleted If it s greater the extra rows are added on the bottom of the table Edit Filter Command Filters a peak valley or alternate mean history from the Loading Window within a fixed amplitude
162. te of the events or gt gt cycles to be plotted in the Damage Curve 2D Crack Graph in the Main Window after the bidimensional crack growth calculations Graph 2 Option Option to plot or not the Elliptic Cracks Graph in the Main Window Graph 2 Data List of the fields that can be plotted in the Hysteresis Loops Elliptic Cracks Graph in the Main Window after the bidimensional crack growth calculations If the Cracks value is chosen from the list then the semi elliptical crack fronts are plotted Graph 2 Sampling Sampling rate of the events or gt cycles to be plotted in the Hysteresis Loops Elliptic Cracks Graph in the Main Window after the bidimensional crack growth calculations OK Button Calculates bidimensional crack growth using the da dN Method for the Loading Window loadings using the material properties and the chosen options and goes back to the Main Window Cancel Button Cancels the bidimensional crack growth calculation and goes back to the Main Window 71 Calculation Logbook Window Stores the total damage and the residual life of the specimen or the average da dN and the total crack growth for crack growth calculations for all the calculations performed by ViDa in the current session The Calculation Title field in the calculation windows such as the Calculate Life SN window is also stored in order to easily compare the results of different calculations Note that if the Loading Time is not set in the Mai
163. the Loading Window Fill out the Loading Time field with the duration in seconds of ALL the loading history in order to calculate the estimated residual life in days of the piece 2 If the loading is a sequential history you might want first to Check or Filter it Unless your loading history comes from an histogrammer as a set of Alternate Mean no of half cycle components thus not keeping order or sequencing information it is recommended to use a rainflow counter Make sure that the history in the Loading Window is expressed as a Peak Valley sequence by clicking on Peak Valley in the Sequencing Option enter a value for the amplitude Filter optional and then click Life Rainflow The Loading Window will then contain the Rainflow filtered Peak Valley history 3 If you want to use a different material from the one shown in the Loading Window go to the Materials database window and choose the desired material or query for materials with certain desired properties in which case the Find Material window will appear Note that you can alter the material properties but you ll need to save the changes using the File Save command prior to any calculations It is possible to estimate properties or calculate them from experimental data please refer to the How do Use the Materials Database topic for more information After choosing the desired Material click on the File Exit command to return to the Main Window 4 Click on Life SN Me
164. thod to enter the Calculate Life SN window 5 Enter the Calculation Title in order to further identify this calculation in the Calculation Logbook window 6 Choose the Surface Finish Type of Loading and enter the Equivalent Diameter Ultimate Strength Su the default value is loaded from the Materials Database and the Operating Temperature of the specimen These choices are used to automatically calculate the values of the endurance limit modifying factors ka kb kc and kd Note that you can calculate the effective diameter for circular rectangular channel or I beam cross sections under bending using the Calculate d Effective Diameter button In this case the Calculate Effective Diameter window will appear You should click on the associated tab of the desired cross section and bending axis enter the cross section dimensions and click on the desired value The resulting equivalent diameter will be displayed By pressing OK you ll return to the Calculate Life SN window carrying the calculated value 7 You can alter directly the values of ka kb kc kd and ke and the value of the uncorrected endurance limit Sf prior to the calculations Note that the next time you call the Calculate Life SN window the ka kb kc and kd values will retain the options chosen in step 6 meaning that altering their values directly will only affect the current calculation 8 Choose the type of SN curve you want to use among Automatic b Sf Nf or b c Nf a
165. tial fate J xlakc m xh Events 172 Cycles Kms No Retardation E x for each 1 e 30000 aa v 30 X 2 1 008 00 1 00 00 Cancel 69 Retardation Effect Option of retardation effects due to overloads Retardation Effect Help Button Shows a window with some information about the Retardation Effect models used by ViDa No Retardation Option Option not to consider crack retardation effects Wheeler Option Option to use the Wheeler retard effect correction Here da dN is multiplied by the factor PZi PZol aol ai wh where wh is the Wheeler exponent PZol and aol are the plastic zone and crack sizes on the overload and PZi and ai are the current plastic zone and crack sizes Modified Wheeler Option Option to use the Modified Wheeler retard effect correction Here deltaK is multiplied by the factor PZi PZol aol ai whm where whm is the Modified Wheeler exponent PZol and aol are the plastic zone and crack sizes on the overload and PZi and ai are the current plastic zone and crack sizes da dN Factor Option Generalization of the Wheeler Option where da dN is multiplied by an arbitrary equation defined by the user To choose from some pre defined equations press the Open button next to this option deltaK Factor Option Generalization of the Modified Wheeler Option where deltaK is multiplied by an arbitrary
166. tions Database through the Name list The formula can also be edited by the user Save As New Button Adds the Kt equation present in the Kt Formula field to the Equations Database The user will be asked to enter a name for this new equation Variables Table Table containing variables that can be set by the user To set a variable just click on it and type its new value If these variables are present in the Kt Formula then their values are used in the calculations Open Variables Button Loads a previously saved Variables Table file var containing the values of all variables from the Variables Table Save Variables Button Saves the values of the variables from the Variables Table to a Variables Table file var Calculated Kt Calculated value of Kt stress concentration factor This value is automatically calculated for the chosen equation using the Variables Table values OK Button Returns to the previous window and copies the Calculated Kt value to the Kt field in the previous window Cancel Button Returns to the previous window without carrying the Calculated Kt value 47 Calculate Notch Sensitivity q Window Calculates the notch sensitivity q Type the value of the notch radius and ViDa will automatically calculate the value of q depending on your choice of material type in the Material option Press the OK button to go back to the previous window bringing and updating the calculated value of q or Cancel to
167. tivates the Calculate b and c for SN window that lets the user calculate the constants of the SN curve N S b c from the material properties Su and Sf After the calculation the estimated b and c values are color coded in red eN Curve Shows the eN curve of the material and also its elastic and plastic components separately The SN curve is also plotted in order to make a comparison with the elastic component of the eN curve The graph is only updated after the property changes are saved To expand or shrink the graph just double click on it Sigmaf Elastic coefficient used in Coffin Manson s eN Curve equation de 2 Sigmaf E 2N b epsilonf 2N c epsilonf Plastic coefficient used in Coffin Manson s eN Curve equation de 2 Sigmaf E 2N b epsilonf 2N c b eN Elastic exponent used in Coffin Manson s eN Curve equation de 2 Sigmaf E 2N b epsilonf 2N c c eN Plastic exponent used in Coffin Manson s eN Curve equation de 2 Sigmaf E 2N b epsilonf 2N c Calculate b c Button Experimental Points Command Loads the values of the parameters b c Sigmaf epsilon of the curve de 2 Sigmaf E 2N brepsilonf 2N c from the Experimental Points tab directly into the current tab da dN Curve Shows the da dN curves of the material using Paris and Elber laws Note that the value of deltaKth substantially affects the Elber law curve The graph is only updated after the property changes are saved
168. u The value of q is calculated from r and Su and taking into account if the current material is a steel or an aluminum for other types of material the steel values are used OK Button Returns to the previous window and copies the Calculated Kt value to the Kt field in the previous window If the previous window is the Calculate Life SN window then the value of q is also carried Cancel Button Returns to the previous window without carrying the Calculated Kt value 46 Calculating Stored Stress Concentration Factors Kt You can calculate the stress concentration factor Kt from stored Kt equations in the database just choose the desired equation name from a list You can also set the variable values in the Variables Table by clicking on the desired cell or edit the equation in the Formula box ViDa automatically calculates the value of Kt for the chosen equation fe Stress Concentration Factor Kt shaft fillet Tension 0 25 lt h r lt 2 0 0 25 lt h r h r lt 2 0 0 92 71 149 sqr h r D DBb5 hr 0 011 3 029 sqr h r 0 948 h7r 2 h7D 0 30443 979 sqr h7r 1 737 h7 rp 27h D 2 0 355 2 098 sqr h7r 0 875 hZ7rp 2 h D 3 P OT D 2hy7h 2 33E 00 Cancel Kt list List of names of the available Kt equations from the Equations Database Just click on the desired name to load its Formula Formula Formula of the Kt equation loaded from the Equa
169. u can either click Material Browser on the Data menu or go to the Material window and click Browser on its Tools menu The simplest way to create a new material on the Material window is to click Clear All Properties on the Edit menu type in the material name type and known properties click Estimate Using Nominal Values on the Tools menu to estimate the unknown properties and click Save As New on the File menu The properties in red on the Material Database denote properties that were calculated estimated from others without having been directly measured or imported from a reliable reference This color can be toggled by pressing the Space bar on the desired field don t forget to save after To estimate unknown material properties on the Material window click Estimate Using Nominal Values on the Tools menu Each missing property is estimated from nominal values and the remaining known properties and it is color coded in red For more information on the estimates click on the Estimates Help button To toggle between True or Engineering stress strain hardening curves on the Material window right click the graph with the mouse and choose the desired option You can store experimental data points for the each material on the Material window SN eN and da dN Paris or Elber curves can be automatically fitted to these points and the calculated properties data can be used in future calculations To import a CSV file csv into an exper
170. u still have problems run the AIIFiles Vbrun60 exe file from your CD and retry the above 108 Problems While Running ViDa The numbers after the decimal point in any text box are disappearing after type them Check if the Decimal Symbol from the Regional Settings Windows Control Panel is set to a point ViDa may not work properly if the decimal point is set to comma Data from a CSV comma separated value file is not properly loaded to ViDa Check if the List Separator from the Regional Settings Windows Control Panel is set to a comma can t load an Excel file into ViDa You need to have Microsoft Excel 97 or later installed in your machine to open Excel files in ViDa can t see the ViDa papers ViDa installs all necessary files to display the slides in your machine However if you still have a problem you can install Microsoft PowerPoint Viewer by running the installation file Vueo6k10 exe located in the Media sub directory of ViDa When I run ViDa receive a message that some file is missing The ViDa CD contains copies of all installed files in the AllFiles directory Copy the missing file to the hard disk and retry running ViDa You might need to uncheck the Read Only attribute of the copied file in your hard disk Database Information The ViDa database contains properties of all materials used in the program and also the Kt KI and da dN equations database It is a Microsoft Access 97 d
171. ular or Delta Rosette using the measured strain values from the Rosette Table Calculate Button Projected Strain Command Calculates the Projected Principal Strain in the direction defined by the Direction field for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table Calculate Button Maximum Stress Command Calculates the Maximum Principal Stress for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table the Poisson coefficient and the Young modulus E of the current material Calculate Button Minimum Stress Command Calculates the Minimum Principal Stress for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table the Poisson coefficient and the Young modulus E of the current material 76 Calculate Button Projected Stress Command Calculates the Projected Principal Stress in the direction defined by the Direction field for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table the Poisson coefficient and the Young modulus E of the current material Calculate Button Principal Direction Command Calculates the direction of the Maximum Principal Strains in degrees for a Rectangular or Delta Rosette using the measured strain values from the Rosette Table Use this command to get an idea of the average direction of the main loadings in your history You might want after to project the strain
172. ulate the effective diameter and press the OK button to return to the previous window with the calculated value 10 mm k t 2 mm Axis 1 1 5 1 11651396564 mm AXIS 2 2 8 08 mm Effective Diameter 5 1 1E 00 mm Cancel Cross Section Tabs Drawings Drawings of the cross section profiles of the available bending effective diameter equations Axis fields Calculated effective diameter under bending on each axis of the chosen cross section To copy any of these values to the Effective Diameter field click on the desired Axis field Effective Diameter Shows the calculated effective diameter for the chosen cross section profile OK Button Returns to the previous window and copies the Calculated Diameter value to the Equivalent Diameter field in the previous window Cancel Button Returns to the previous window without carrying the Calculated Diameter value 44 Calculate Typical Stress Concentration Factor Kt Window Calculates the stress concentration factor Kt for typical specimens Clicking on the desired specimen category 3 or 4 figures will appear on the screen Enter the values of w or D d and r and click on the figure with the desired specimen type ViDa will then calculate the value of Kt and plot the Kt equation that originated this calculation The values of the notch sensitivity q and the effective stress concentration factor Kf 1 q Kt 1 are also displayed considering that the current mate
173. ulations The components of the Tridimensional table are combined using Mises Tresca and the resulting history is shown here Transfer Button Copies the calculated Equivalent Peak Valley Table values to a new Loading Window on the Main Window Exit Button Exits the Calculate 3D Equivalent Stress Window and goes back to the Main Window 74 Rosette Peaks and Valleys Tab Calculates equivalent stresses and strains for a list of strain triplets measured from a rectangular or delta Rosette The user can calculate the maximum or minimum equivalent stresses strains their principal direction angle or the projected stresses strains onto a user defined direction angle The Rosette Peak and Valley Table can be saved to or loaded from a file The calculation results can be copied to a new Loading Window in the Main Window a E guivalent Stress Tridimensional Peaks and Yalleys Rosette Peaks and Valleys pe Poisson 0 292 mn MPa E Youngk 203 GPa airy Lr iul Transfer Strain ue Direction degr Peak V alley Equivalent Rectangular 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Peak Valley Type Option Lets the user choose between calculations from 3D tensor components or from Rosette measurements If the Tridimensional option is chosen then the Calculate Rosette Equivalent Stress Window turns into the Calculate 3D Equivalent Stress Window Rosette Table Table from the Calculate Ros
174. using the Tools Options Simplified command in the Main Window prior to calculating life After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations SN Curve Tab Calculation title SH Curve Automatic C b SENE 396 9 C b c Nt 352 941 j 9 49 00 EM 4 53 27 n 435 294 in L S CZ Ll L LL IL d 1d Lo 1 EE 3L 1000 10000 100000 1 006 191 042 X Consider SN Curve Elbow 1 007 belb 0 00 00 N Ground Surface Finish 220 5 Type of Loading Tension Effective Diameter 10 Su 441 MPa Operating Temperature 24 2 00E 00 H 01 Calculation Title 9428 01 ioo 00 Az3b01 La 00E 00 00 00 DUE 00 Title of the calculation that is about to be performed This is an optional field useful to identify and compare results from different calculations in the Calculation Logbook Window Type of SN Curve Option ViDa considers ways of obtaining the SN curve N S bzc
175. ut specimen characteristics such as its total width and crack initial size alter the material Paris or Elber law constants and choose a stress intensity factor equation loaded from the Equations Database Some of the default data in this window comes from the Materials database and the rest is maintained from your last calculation Many more options are available in the extended Crack Growth da dN window which is available by using the Tools Options Simplified command in the Main Window prior to calculating the crack growth After tuning the desired properties just click on the OK button to return to the Main Window and perform the calculations Kic 1 30 02 x pans 14 77 E 07 Ez m 2 DUE 00 Paris 5 33 07 Eg X Elber m 2 00E 00 Elber 0100000 0010000 0001000 0000100 0000010 0000001 E agat Initial Crack 1 00E 00 mm Final Value 0 00 00 mm if Final V alue l criterion is ignored Width w 5 00E 02 mm To check information on the available commands please refer to the correspondent extended window 65 Bidimensional Crack Growth da dN and dc dN Window Calculates bidimensional crack growth using the da dN Method combined with elliptical cracks stress intensity factor equations and the loading history from the Main Window The cracks are assumed elliptical in shape with semi axis a
176. values using the distortion energy Mises criterion Note that even though the Mises criterion calculates absolute values ViDa includes a sign in the equivalent Peak Valley history This sign is fundamental when calculating fatigue life otherwise the tension compression information would be lost Calculate Button Tresca Command Calculates an equivalent Peak Valley history from the Tridimensional Table values using the maximum shear stress Tresca criterion Calculate Button Maximum Principal Stress Command Calculates the Maximum Principal Stresses from the Tridimensional Table values and puts the result in the Equivalent Peak Valley Table The Maximum Principal Stress is the greatest value among the 3 principal stresses e g if Sx 20 Sy 5 Sz 10 then the MPS is 10 This command is very useful for crack growth calculations since the crack tends to grow in the maximum tensile stress direction the magnitude of compressive stresses doesn t influence crack growth Calculate Button Maximum Absolute Principal Stress Command Calculates the Maximum Absolute Principal Stresses from the Tridimensional Table values and puts the result in the Equivalent Peak Valley Table The Maximum Absolute Principal Stress is the greatest value among the absolute values of the 3 principal stresses e g if Sx 20 Sy 5 Sz 10 then the MPS is 20 Equivalent Peak Valley Table Peak Valley table containing the output from equivalent loading history calc
177. ven a desired geometry and Su the Calculate Kt button Stored which goes to the Smart Calculator window and calculates Kt from previously stored equations in the Kt Equations Database or the Calculate q Notch Sensitivity which goes to the Calculate Notch Sensitivity for Steels and Alumina window and calculates q for steels or alumina given Su and the notch radius commands 15 Check if all options are set as desired and press the OK Button The damage and residual life will be calculated and shown in the Loading Window Note that the residual life in days depends on the Loading Time value from the Main Window 88 How do Calculate Damage of Welded Structures To calculate the fatigue damage and the remaining crack initiation life of a welded structure which works under elastic stresses you should use the IIW method Below there is a complete list of all steps you might need to go through to perform this calculation 1 Load a Loading History or type it in the Loading Window Fill out the Loading Time field with the duration in seconds of ALL the loading history in order to calculate the estimated residual life in days of the piece 2 If the loading is a sequential history you might want first to Check or Filter it Unless your loading history comes from an histogrammer as a set of Alternate Mean no of half cycle components thus not keeping order or sequencing information it is recommended to use a rainflow counter M
178. ws the Options window where the user can set the ViDa general options regarding Editing of the Loading histories the Modeling option used for all calculations Extended or Simplified the Units used SI or English and the idiom used on the user interface among English Portuguese French German Italian Spanish and more This command has the same functionality as the Tools Options command Data Menu Material Equation Find Material Browse Material Data Material Command Goes to the Material window to select a different material for the calculations Data Equation Goes to the Equation Database window where you can work with e stress concentration factor Kt to add delete or change Kt equations that will be available for future SN IIW and eN calculations e stress intensity factor database to add delete or change KI equations that will be available for future da dN and Bidimensional Crack Growth calculations e crack growth equations da dN database to add delete or change da dN equations that will be available for future da dN calculations Data Find Material Command Goes to the Find Material window where the user can search for materials by their type steels alumina etc or by any property ranges e g materials with Su between 600 and 800 MPa or combinations of them You can also sort the matching materials by any property Data Browse Material Command Goes to the Browse
179. y of the calculations The user can also enter an initial residual stress value Initial Residual Stress Initial value of the residual stress on the specimen use negative values for compressive residual stresses Residual stresses are only considered in the life calculation if the Consider Residual Stresses Option is on Plot Loops Range of hysteresis loops that the user wants to plot for visualization purposes This range doesn t affect the calculations the program needs to calculate ALL the hysteresis loops in order to consider residual stresses accurately Note that residual stresses are only considered in the life calculation if the Consider Residual Stresses Option is on Points for Calculation and Plotting Resolution in number of points of each hysteresis loop for calculation accuracy and plotting purposes For calculation 40 points is in general a good choice If you re plotting too many hysteresis loops you might have to reduce the number of plotting points for each loop Linear Neuber Option Strain concentration theory used when considering stress concentration factors on hysteresis loops Linear theory considers Ke Kt strain concentration Ke is equal to Kt while Neuber theory uses Ke Ks Kt 2 Kt Stress concentration factor of the specimen relating the nominal loading to the stresses at the notch root Its value can also be calculated using the Calculate Kt Typical or Calculate Kt Stored commands q Notch se
180. you want to use in the calculations and press the OK button The total and average crack growth in both directions are almost instantly displayed on the 2 bottom rows of the Loading Window What s next ViDa still has many other features Rainflow counters Tridimensional Stress handling Rosettes Stress Concentration Factor tables and much more To know more about ViDa refer to Working with ViDa Windows see the Contents CHAPTER 2 Installing ViDa It is quick and easy to install in your computer The CD ROM features autorun and a setup wizard making the installation process easier than ever Contents Before You Begin Running ViDa Setup Installing ViDa Viewing the Book Fatigue Design under Complex Loading Registering ViDa Before You Begin Before you install ViDa make sure your computer meets the following minimum requirements 486DX 66 MHz or higher processor Pentium or higher processor recommended Microsoft Windows 95 or later operating system or Microsoft Windows NT operating system version 4 0 with Service Pack 3 or later 16 MB of RAM for Windows 95 or later 32 MB recommended 24 MB for Windows NT 4 0 32 MB recommended Hard disk space required for typical installation 45 MB CD ROM drive VGA or higher resolution monitor Super VGA recommended A mouse or other suitable pointing device To run Setup you need to have the ViDa CD or network access to ViDa files Running ViDa S

User Manual - PUC-Rio

Contents

Download Pdf Manuals

Related Search

Related Contents