ATENA Program Documentation Part 4
Contents
1. 2 8981566 Relative error Max U x 0 Min U_x 0 Max U_y 0 Min U_y 0 1 4990783 Max U_z le 010 Min le 010 Max X 21600 000 64800 000 86400 000 Es V PipeBTemp msg BEES Iter Rel Humid Rel Temper dbs Humid Abs Temper 1 Let 6 2 9 1e 015 5 2e 014 Step 13 completed Elapsed CPU sec this step 1 672 all steps 20 857 lt Ready Completed i Time 8 6e 004 2 OVR t3 start amp E ET win fS sky 5 Inb Sof GID g te G tay Tut Figure 9 The runtime display of temperature field during the thermal analysis in ATENA After the thermal analysis is completed AtenaWin can be closed All resulting files are stored in the subdirectory AtenaTransportCalculation of the PipeBTemp gid directory In this subdirectory the following files will exist after the completion of the thermal analysis PipeBTemp inp ATENA input file created by GiD and used by AtenaWin PipeB 00xx Binary result files created by ATENA during the thermal analysis These two files are created in the Tutorial Temperature2D directory PipeB Results thw saved temperatures to be used by stress analysis Geometry bin saved geometry to be used for the interpolation of temperatures in the stress analysis 3 STRESS ANALYSIS After the thermal analysis 15 completed AtenaWin can be closed and the stress analysis can be performed using the calculated thermal fields A2. i n d e e x 1 ID D E7 ak FADO I a NT GENS 2 IO E Hl Hoot s y b File written to C X amp tenaE amp amplessAtena GID T utorial T emperature2D PipeB Static gid amp tenaR esults inp File written OK Command ER i amp Total Commander Ba cc seminar 2008 ta Tutorial Atena Eng GiD 4 AtenaV4 Stat E Calculator CiWINDOWSIsys Figure 16 Importing results for postprocessing in GiD 14 Oeo Gq isadgi ose 9 8 pim Ade A a NR es o ET 4 Pa m xx oF NEE 5 6 Vx d eM DS Im Postprocess Read EF Preview Directory E AtenaCalculation ISA amp 1 svn AtenaResults flavia msh poy RET KD File name AtenaResults flavia res Open v Cancel Files of type GiD postprocess res msh bin y b File written OK Enter name of file to read Command amp Total Commander 7 0 cc seminar 2008 O9 m Tutorial Atena Eng Te GiD4 AtenaV4 Static Calculator Figure 17 Opening results for postprocessing in GiD The results can be then postprocessed Figure 18 shows crack width as contour lines which can be selected by the menu command View results Contour lines CRACK WIDTH CODI The command can also be accessed from the E icon
3. LU E rc Extend Accuracy F Line Search Method i Conditional Break Criteria Step Stop Displacement 100000 Iter Stop Displacement 100000 Step Stop Residual 100000 Iter Stop Residual 100000 Step Stop Energy 100000 Iter Stop Energy 100000 Master Slave Distance 1 0E 4 actor Extrapolation Nearest IP Show Surface Loads In Post Processor Write Monitor Data Close Problem Data E k Global Settings Time and Transport Restart Calculation from Calculated Step Integration of Transient Theta of Crank Nicholson 0 7 v Espot Transport Results Export Results Ta PipeB He Export Geometry Tao FipeB Ber Close Figure 6 Problem data dialog including the definition of temperature exchange files with stress analysis The problem data dialog that is shown in Figure 6 can be opened via the menu item Data Problem data This dialog can be used to define the basic parameters for the thermal analysis The most important fields can be found at the bottom of the Time and Transport tab where the names of two files are to be specified These files are used for exchanging the temperature fields with the subsequent stress analysis By default the files would be stored in the AtenaTransportCalculation subdirectory of the main problem directory inserting before the names writes them into the Tutorial Temperature2D directory The ATENA calculation is started from the menu ATENA A
4. RATE FACTOR Item Min 1e 010 RATE FACTORS eum SOFT HARD PARAMETER STRAIN L STRESS E TENSILE STRENGTH Cancel TOTAL ELEM BODY LOAD v rar er nm memi Apply Filter HI 1 1 1 0 21 0 052 0 21 NR 2 1 0 014 0 017 0 0041 0 00023 NR 3 1 0 0011 0 0013 0 00032 1 4e 006 Step 1 completed Elapsed CPU sec this step 3 282 all steps 3 282 Job Step 2 Log start 26 2 2009 12 28 11 Iter Eta Disp Err Resid Err Res Abs E Energy Err NR Iter Eta Unbalanced Energy Ratio Current Required L3 t 1 0 5 0 11 0 026 0 054 NR F1 Ready Back substitution amm IDofjBlk 500 Time 2 2 OVR a amp Total Commander ga cc seminar 2008 taj Tutorial Atena Eng GiD AtenaV4 Stat FE Calculator AtenaWin M CCSt Figure 13 Execution of static analysis in AtenaWin and the selection of crack opening display 1 gse cn 9 5 Cu T TSH eR OLM gM KD E Set 1 ConvergenceMonitor E CRACK WIDTH at location ELEMENT NODES for item COD1 BAR Convergence criteria 1 4 LEGEND 3 1 0000000 2 7094e 007 23708e 007 20321e 007 16934e 007 0 7500000 13547e 007 1 16 007 6 7736e 008 3 3868 008 0 0 5000000 x 2 i o zl pu 9 v 5 3 Max Ux 126 005 Min U_x 0 Max U_y 126
5. The loading is subdivided in 3 intervals In the first interval 12 load steps are defined with boundary conditions as described in Figure 3 In each step the temperature on the outer surface is increased by 1 C see Figure 3 The temperature in the exterior is increased up to 37 C starting from the initial uniform 25 C Each step in this interval represents 3000 seconds thus the whole interval covers the period 0 36000 seconds 0 10 hours b Figure 3 Boundary conditions for the interval 1 In the subsequent interval 2 the temperature at the outer surface 1s kept constant This interval contains 10 steps 2880 seconds long This means the whole interval spans the time period from 36000 64800 seconds 10 hours 18 hours b Figure 4 Boundary conditions for the interval 2 In the last interval 3 the outer surface 15 cooled back to 25 degrees This interval contains 12 steps 1800 seconds long This means the whole interval spans the time period from 64800 86400 seconds 18 hours 24 hours y d Figure 5 Boundary conditions for the interval 3 Problem Data E 5 Global Settings Time and Transport Restart Calculation from Calculated Step Title Pipe T askM ame Pipeb Method Displacement Error 0 0001 Residual Error 0 0001 Absolute Residual Error 0 0001 Energy Error 0 000001 Iteration limit 30 Optimize width Sloan Stiffness type Tangent Predictor Assemble Stiffness Matris Each Iteration Solver
6. new GiD problem must be created or the existing problem PipeBStatic gid can be used This model defines the input for stress analysis of the same pipe wall as was used in the thermal analysis The geometrical model and boundary conditions are shown in Figure 10 NS Figure 10 Geometrical model and boundary conditions for stress analysis In order to be able to utilize the thermal fields calculated during the thermal analysis the appropriate import files must be specified in the problem data dialog that 15 activated from the menu Data Problem data and 15 shown in Figure 11 This information 15 located in the bottom 2 input fields where appropriate file names are specified including their path Problem Data Global Settings Global Options Transport Restart Calculation from Calculated Step Title demo default title for Static analysis T askMame Pipe Static Method Mewtan Haphson Displacement Error 0 01 Residual Error 0 01 Absolute Residual Error 0 01 Energy Error 0 0001 teratian Limit 60 Optimize Band width Sloan l Stiffness Type Tangent Predictor Assemble Stiffness Matris E ach Iteration Solver LU Extend Accuracy Factor W Line Search Method Line Search With Iterations Line Search With Iterations Unbalanced Energy Lint 0 8 Line Search lteration Limit 3 linimum Eta 0 1 Maximum Eta Conditional Break Criteria Close Problem Data Global Settings Global Options Transport
7. 005 Min U_y 0 Max le 010 1 le 010 0 2500000 Max 12 Min X 0 Mx Y 12 Min Y 0 Max Z le 010 le 010 8 8 8 Max Val 276 007 e e e e Z e i e e e e e e e e e vi j 2 V PipeBStatic msg mE Job Step 4 Log start 26 2 2009 12 30 50 Iter Eta Disp Err Resid Err Res bs E Energy Err NR Iter Eta Unbalanced Energy Ratio Current Required L3 1 1 0 26 0 39 0 13 0 099 NR 1 1 0 62 0 8 LS 2 1 0 0076 0 32 0 11 0 0024 NR 1 1 0 85 0 8 LS 3 1 0 0095 0 27 0 094 0 0026 NR 1 1 0 86 0 8 LS 4 1 0 0079 0 23 0 062 0 0018 NR 1 1 0 86 0 8 L3 5 1 0 0068 0 2 0 072 0 0014 NR a Ready Assembling Group 233 Elem 492 Time 4 6 OVR A Figure 14 Execution process of stress analysis in AtenaWin showing the crack opening displacements After the completion of the analysis the AtenaCalculation subdirectory of PipeBStatic gid contains the following files PipeBStatic inp ATENA input file created by GiD and use
8. 15 Moscow ail d Cog 2669 F SAO ABE 8 gk Fg UN M Im ONS Ke 9 Ni D tv s SAP amp no AN a NS PNE 2 DGD Fave i iw 0 8e 05 7118 05 8 6 4622e 05 2933e 05 4446 05 3 2 A 9 556e 06 667e 06 776e 06 888e 06 op D step 50 Contour Lines of CRACK WIDTH COD1 Contour Lines CRACK WIDTHI Min 0 Max 1 88e 005 es COD1 Min 0 Max 1 88e 005 Contour Lin man Comman d Figure 18 Displaying crack opening displacement isolines in GiD 4 2 Postprocessing in ATENA 3D The highest user comfort for post processing is provided by Atena 3D After executing ATENA 3D the result file for each increment can be loaded into the program by using the menu File Open other Results by step This command activates a dialog that can be used to load ATENA binary files with results to ATENA 3D postprocessor When the user finishes loading the needed result file and closes the dialog ATENA 3D postprocessor is automatically started It should be noted that it 1s possible to open only binary result files that come from the same analysis For further details about post processing the user should consult the Part 2 2 of ATENA user s manual 2 5 CONCLUSIONS This tutorial provided a step by step introduction to performing combined thermal and stress analysis using ATENA software with GiD preprocessor The tutorial involves an exam
9. CERVENKA CONSULTING Cervenka Consulting Ltd Na Hrebenkach 55 150 00 Prague Czech Republic Phone 420220 610 018 E mail cervenka cervenka cz Web http www cervenka cz ATENA Program Documentation Part 4 5 Tutorial for thermal analysis Coupling of thermal and stress analyses Written by Jan Cervenka Dobromil Pryl Prague Aug 20 2009 Copyright 2000 2009 by Cervenka Consulting Trademarks Microsoft and Microsoft Word are registered trademarks of Microsoft Corporation TABLE OF CONTENTS 4 1 4 2 INTRODUCTION isse esee voe eT oov s ee eia evee uve vv doe Fosva Ua TO VUE Yu COT UU oe Eee E NU V UT ee UU NEL VE OUT E CGU 1 THERMAL ANALYSIS 5i eioei tee vv aa deo eU ava rU vv Nae FUT Val Cdeb d Dey dp esie ue veo lev v aee eU vea eU depo FURENT ET UN 1 STRESS ANALYSIS 8 POSIPROCESSING a 12 Postprocessing In GID 13 ob eee eee SaaS US NN PR aa 0a 16 o M 16 LITERATURE ocu a Cena ota Osa avo Op 18 1 INTRODUCTION This document describes an example of rotationally symmetrical vessel subjected to thermal loading The analysis is performed using the programs ATENA and GiD ATENA is used for thermal and static analysis and the program GiD 15 used for data preparation and mesh g
10. CES INTERNAL FORCES PARTIAL EXTERNAL FORCES FORCES PARTIAL REACTIONS REACTIONS PSA TIGL RESIDUAL FORCES RESIDUAL FORCES PHYSICAL PARAMETERS STRAIN PRINCIPAL STRAIN STRESS PRINCIPAL STRESS TENSILE STRENGTH FRACTURE STRAIN PRINCIPAL FRACTURE STRAIN MAKSIMAL FRALT STRAIN CRACK WIDTH PERFORMANCE INDE PLASTIC STRAIN PRINCIPAL PLASTIC STRAIN SOFT HARD PARAMETER EQ PLASTIC STRAIN REFERENCE NODAL COORDINATES Llose Figure 15 Selecting results for postprocessing in GiD The menu command ATENA GiD Post processing or the icon toggles GiD between pre and postprocessing A warning about non existent res file may appear then a console windows is started and the results are converted into a format readable by GiD see Figure 13 16 The conversion can take a few minutes depending on model size number of load steps and the number of quantities selected for postprocessing The results are stored into the AtenaResults flavia res file in the AtenaCalculation respectively AtenaTransportCalculation directory for static analysis respectively transport analysis This file can be opened in GiD by the File Open command see Figure 17 Local L A N Y London Tokyo Moscow Delhi Singapore Sydney UTC a Ed 9 e oSv 9 8 Dil versions a No B F et Ye g o we 4 FEX x32 EM C WINDOWS system32 cmd exe Converting script res ATENA gt GiD es MI DS Im
11. Restart Calculation from Calculated Step iw Import Transport Results 7 Import From Results PipeB He Import From Geometry PipeB Bec Close Figure 11 Problem data dialog including the definition of temperature exchange files The loading history is specified in a single interval The interval is divided into 50 load steps In each step the temperature difference of 720 seconds from the thermal analysis is applied Figure 12 So the interval spans the period of 10 hours 1 e it only covers the heating phase The Transport Import switch set to Interval Beginning means the thermal analysis results are only imported once and the temperature values are interpolated for each static analysis step For complex temperature histories it can be changed to Each Step Interval Data h 0 0 50 5 2 5 Basic Parameters Eigenvalue Analysis Iw Interval ls Active Load Mame temp load Interval Multiplier 1 0 Number of Load Steps 50 Store Data for this Interval Steps SAVE ALL Fatigue Interval ML iw Read Transport Data Transport Import INTERYAL BEGINNING Interval Starting Time hour Interval End Time 10 hour Iv Delete BC Data After Calculation User Solution Parameters Close Figure 12 Interval data for the interval 1 The stress analysis is again started by selecting the menu item ATENA ATENA analysis or the icon This starts the AtenaWin program The analysis is started automatic
12. TENA analysis or by clicking the calculator icon 1 This will start AtenaWin program which 15 a graphical interactive environment for the execution control of ATENA finite element core module More details about the usage of this program can be found in the corresponding ATENA manual 5 After executing ATENA analysis the following window appears on the user s computer see Figure 7 wusste uses EBS 5 0 8 mW Go Eg NEG J B m ed e Le ES x D E Set 1 ConvergenceMonitor mE E Geometry Seles Convergence criteria 1 4 Relative error V PipeBTemp err ATENA Version 4 1 3 2241 c Cervenka Consulting 1998 2008 Load step 1 at time 6000 Ready Assembling Stiffness Internal Forces Group 463 Elem 204 Time 6e 003 1 OVR start s e Tot Eiwi Sk S Inb Sof GiD g Ate Figure 7 The main AtenaWin window after its activation from GiD The ATENA analysis is started automatically or by clicking the zs button This starts the thermal analysis in AtenaWin environment In order to visualize the development of the temperature field the button sm can be selected and this will open a dialog that is shown in Figure 8 In this dialog various variables can be selected for display The temperature fields can be displayed by selecting CURRENT PSI VALUES Temper m BSA PARE CH NS B ssmessxWwE 5 x E Gg 6 a t be E Set 1 ConvergenceMonitor Seg E Geom
13. ally or by clicking the button This starts the stress analysis in AtenaWin environment In order to visualize the development of the various data fields the button um can be selected and this will open a dialog that 15 shown in Figure 13 In this dialog various variables can be selected for display The contour areas of crack width can be displayed by selecting Elements CRACK ATTRIBUTES CODI The resulting computer screen in shown in Figure 14 The imported temperature values can be displayed as ELEM TOTAL TEMPERATURE TotalTemp Please note that only the difference from the reference initial temperature 1s displayed in static analysis 10 am BINS t B uu 6 saw WEB Fea aay ase E Set 1 ConvergenceMonitor Seg 3 SH 8808 0 7500000 pei Post processor data 0 5000000 x Available data General 1 z M Draw output Relative error ELEM TEMPERATURE INCR ELEM TOTAL TEMPERATURE Max U_x 576 006 ELEMENT DRIENTATION Location EQ PLASTIC STRAIN FRACTURE STRAIN C Global nodes Max U_z le 010 Mm U_z le 010 0 2500000 MAXIMAL FRACT STRAIN NONE Element nodes PERFORMANCE INDEX C l PLASTIC_STRAIN 4 aisha Meck 12 PRINCIPAL_FRACTURE_STRAIN 1 C Elements IPs Mm 0 PRINCIPAL PLASTIC STRAIN Mev 12 PRINCIPAL_STRAIN MY PRINCIPAL STRESS Mex Zo 1e 010
14. d by AtenaWin PipeBStatic 00xx Binary result files created by ATENA during the stress analysis 4 POSTPROCESSING Postprocessing can be done either in AtenaWin GiD or Atena 3D Normally AtenaWin displays the current step that is analysed After the analysis is finished the last step remains in AtenaWin memory and can be visualized and further post processed In case the user wants to post process results from other load step the corresponding step results file is to be opened using the command Application Restore FE Model From The step data file name is task name 00xx where task name is the name of the current task as given in the problem data dialog see Figure 11 and 00xx represents the load step number which 15 to be post processed Alternatively the new text window is to be opened using the menu item File New Please note that a text window must be highlighted in order to another text window If 12 graphical window 15 the active one a new graphical window will be opened Into the new text window the following command shall be written RESTORE FROM task name 00xx 4 1 Postprocessing in GiD To be able to postprocess the results in GiD the result quantities must first be made available by selecting them in the Data Problem Data Post Data dialog see Figure 15 Post data M NI NAI SI s I I 5 5 5 DISPLACEMENTS PARTIAL INTERNAL FOR
15. eneration The programs GiD and ATENA can be installed using the standard ATENA installation At the end of the installation the user must select the installation of GiD and ATENA GiD interface After that your computer should be ready to run the example problem described in this document 2 THERMAL ANALYSIS First the program GiD 15 started The recommended version 15 9 0 2 or newer the oldest supported version is 7 7 2b After starting GiD the user should open the example analysis ATENA Science ATENA GiD Tutorial Temperature2D PipeBTemp gid This is an existing model demonstrating the combination of thermal and stress analysis This problem is using the problem type AtenaV4 Transport It represents a section of a pipe wall with thickness of 0 23 m and internal diameter of 1 m Taking advantage of the symmetry only a quarter of the whole crossection is modeled The geometry of the model 1s shown Figure and the numerical model is shown in Figure 2 Details about ATENA GiD interface and associated problem types for ATENA can be found in the manual 6 The same mesh size is used for thermal and static analysis This 15 however not a strong requirement The thermal loading can be exchanged also between models with totally different meshes y b Figure 1 Geometry and material properties of the axisymmetrical pipe model HIT E Hj Ta C Figure 2 Numerical model finite element mesh
16. etry Convergence criteria 1 4 5 8963132 4 4972343 v 9 29881566 E Available data General k CURRENT NODAL COORDINATES Iv Draw output z CURRENT PSI VALUES 0 DISPLACEMENTS 3 EXTERNAL FORCES Location Meaty 0 INTERNAL_FORCES ax U y NODAL DEGREES FREEDOM Global nodes MIU 0 14880183 NODA L SETTING Max U_z 1le 010 NONE C Element nodes le010 PARTIAL EXTERNAL FORCES CE PARTIAL INTERNAL FORCES giii l2 PARTIAL_REACTIONS C Elements IPs Mex o 0 PARTIAL RESIDUAL FORCES Mu 12 Min Y 0 OW Max Z REACTIONS Item 7 REFERENCE NODAL COORDINATES RESIDUAL FORCES s s g START PSI VALUES 2 E Cancel Apply Filter OK P PipeBTemp msg Iter Rel Humid Rel Temper Abs Humid dbs Temper i o 1 7 0 6 2 o 9 1e 015 a 5 2e 014 Step 13 completed Elapsed CPU sec this step 1 672 all steps 20 857 Job ATENA Log end 24 2 2009 15 43 52 v Ready Completed Time 8 6e 004 2 OVR Figure 8 The selection of temperature display in AtenaWin j Singap S for item Temper BH PGR OHMS Bug su wBE AA 59Ww THER eM OLM as ghee KD E Set 1 ConvergenceMonitor X E CURRENT PSI VALUES at location NODES for item Temper Convergence criteria 1 4 CURRENT PSI VALL 5 9963132 Temper 33817 33688 33558 33429 44972348 333 33 17 33041 32912 32792
17. ple of an axisymmetric pipe heated from the outside from 25 to 37 C in 10 hours Then the heating remains constant for another 8 hours and 15 afterwards cooled back to 25 C in 6 hours The objective of this tutorial 15 to provide the user with basic understanding of the program behavior and usage For more information the user should consult the user s manual 2 or 16 contact the program distributor or developer Our team 1s ready to answer your questions and help you to solve your problems The theoretical derivations and formulations that are used in the program are described in the theory manual 1 Experienced users can also find useful information in the manual for the analysis module only 4 17 6 LITERATURE 1 ATENA Program Documentation Part 1 ATENA Theory Manual CERVENKA CONSULTING 2009 2 ATENA Program Documentation Part 2 1 and 2 2 ATENA 2D and 3D User s Manual CERVENKA CONSULTING 2008 3 ATENA Program Documentation Part 3 ATENA 2D Examples of Application CERVENKA CONSULTING 2005 4 ATENA Program Documentation Part 6 ATENA Input File Format CERVENKA CONSULTING 2009 5 ATENA Program Documentation Part 7 AtenaWin Manual CERVENKA CONSULTING 2008 6 ATENA Program Documentation Part 8 User s Manual for ATENA GiD Interface CERVENKA CONSULTING 2008 18
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