Free Size optimization
Altair EmployeeHello everyone,
I am doing a free size optimisation of a composite part for the first time. When i tried to run the model, i get the following error
*** ERROR # 6004 ***
Element 2343640 belongs to SETs 28 and 29, which are used
in GROUP definition on DSIZE card 1. Each element can only belong
to one such SET.
Could someone please help how to deal with this problem?
P.S.: Unfortunately, I could not share the FEM file since the project is confidential.
Thank you and looking forward to hear from you.
Answers
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Hello guys,
Anyone could please look into the issue and help me troubleshoot the problem?
thanks
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Hi Samraj,
Please share us the model file. It will be kept confidential, no need to worry about that. We need to look at your model setup, to help you.
Please use below FT link to share your model.
https://ftin.india.altair.com:8443/filedrop/~osKE8Q
Thank you
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Hello Premanand,
Thank you very much for your response.
1. I checked with my boss and he says i am not supposed it give it out. (I know its not ideal)
2. Actually, i played around a bit. i referenced all the plies to one particular set and it seemed to have eliminated the issue i had been facing.
Now, the results are there. But it looks like no free size optimization was done. I checked 'name of the file, s1.h3d' load case file. the static analysis had run fine. But when i open 'Name of the file_des.h3d', ply thickness, i dont see anything but the target component of blue in color.
Is there anything i missed to add in the model?
thank you
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Did you check for the last iteration?
Thank you
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Hi,
Yes. there were 5 iterations in total. i chose 5th and looked for element thickness and ply thickness results. Fringe was only blue in color.
Thank you
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Please can you share the .out file at least?. So that, i can check the inputs and tell you what is wrong in the model.
Thank you
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Hello,
Sure. I have pasted the entire log file here.
*** OptiStruct defaults set from: install config file: C:\Program Files\Altair\2017.2\/hwsolvers/optistruct.cfg. NOTE # 9199 MSGLMT=STRICT is active, all messages will be printed. You can suppress some less important warning messages by use of MSGLMT=BRIEF or UNREF (in config file or in the input data). 1 PARAM(s) were set: CHECKEL,NO *** WARNING 1932: MAT ID 1 is not referenced. *** INFORMATION # 4739 The structure of surface-to-surface contact element is quite different than that of node-to-surface contact element. No internal CGAP/CGAPG elements are created for surface-to-surface contact. NOTE # 1852 AUTOMATIC SCREENING is activated. Use DSCREEN,AUTO,OFF to disable automatic screening. *** INFORMATION # 6361 There is no user-defined MINDIM for DSIZE card 1 but MINDIM is required when manufacturing constraints, composite optimization, multi-model optimization and/or DOPTPRM,TOPDISC is active. Using MINDIM=8.6955e+000 based on the average mesh size. ************************************************************************ OPTIMIZATION FILE AND PARAMETER INFORMATION : --------------------------------------------- FEM model file :
/Samraj/Dachrahmen/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3.fem Output files prefix : /Samraj/Dachrahmen/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3 Model read from files: /Samraj/Dachrahmen/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3.fem ************************************************************************ ************************************************************************ FINITE ELEMENT MODEL DATA INFORMATION : --------------------------------------- Total # of Grids (Structural) : 259296 Total # of Elements Excluding Contact: 580690 Total # of S2S Contact Elements : 47543 (no internally created CGAPG) Total # of Rigid Elements : 5 Total # of Rigid Element Constraints : 2749 Total # of Degrees of Freedom : 1066876 (Structural) Total # of Non-zero Stiffness Terms : 98661712 Element Type Information ------------------------ CTETRA Elements : 484294 CQUAD4 Elements : 95231 CTRIA3 Elements : 1165 Load and Boundary Information ----------------------------- FORCE Sets : 2 SPC Sets : 2 Material and Property Information --------------------------------- PSOLID Cards : 2 PCOMP(G)(P) Cards : 2 MAT1 Cards : 2 MAT8 Cards : 3 ************************************************************************ ************************************************************************ OPTIMIZATION PROBLEM PARAMETERS : --------------------------------- Objective Function : Minimize Mass ------------------ Response Summary : ------------------ Number of mass responses : 1 Number of displacement responses : 3 ------------------------ Static Subcase Summary : ------------------------ ---------- -------- -------- Subcase ID SPC ID FORCE ID ---------- -------- -------- 1 3 1 2 4 2 ---------- -------- -------- --------------------------- Design Parameters Summary : --------------------------- Total # of free-sizing design elements : 33844 Total # of free-sizing cards : 1 Total Volume of Design Material : 5.7461E+05 Total Mass of Design Material : 8.6192E-04 Volume of Non-Design Material : 3.2272E+06 Mass of Non-Design Material : 4.4494E-03 Composite Design Elements : STACK ------------------------- ------- 2 --------------------------------- Optimization Parameters Summary : --------------------------------- Initial Material Fraction [0,1] : 0.9000 Maximum Number of Iterations : 80 Convergence Tolerance : 5.0000E-03 Step Size (Free Sizing) : 0.5000 Checkerboard Control : On (1 - Global Averaging) Run Type : Free-Sizing Optimization ---------------------------------- Free-Sizing Optimization Summary : ---------------------------------- -------- ----------- ----------- ------- ------- ------- DSIZE ID Minimum Maximum Pattern Pattern Pattern Member Size Member Size Repet. Symm. Group. -------- ----------- ----------- ------- ------- ------- 1 0.8695E+01 NONE NONE NONE -------- ----------- ----------- ------- ------- ------- Restart from previous solution : No Run at location : /Samraj/Dachrahmen/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3/ Scratch file directory : /Samraj/Dachrahmen/2018_07_02_Dach_mit_Dachrahmen_hohl_material_free_size_optimization_v3/ Free space: 304.731 GB Number of CPU processors : 1 ************************************************************************ ************************************************************************ MEMORY ESTIMATION INFORMATION : ------------------------------- Solver Type is: Sparse-Matrix Solver Direct Method Current Memory (RAM) : 2603 MB Estimated Minimum Memory (RAM) for Out of Core Solution : 2352 MB Recommended Memory (RAM) for Out of Core Solution : 2603 MB Recommended Memory (RAM) for In-Core Solution : 12538 MB Recommended Number of Nodes for SPMD Load Decomposition Run : 3 DISK SPACE ESTIMATION INFORMATION : ----------------------------------- Estimated Disk Space for Output Data Files : 3732 MB Estimated Scratch Disk Space for In-Core Solution : 29476 MB Estimated Scratch Disk Space for Out of Core Solution : 42760 MB ************************************************************************ BEGINNING OPTIMIZATION SOLUTION .... ************************************************************************ OPTIMIZATION HISTORY INFORMATION : ---------------------------------- ITERATION 0 (Scratch disk space usage for starting iteration = 31650 MB) (Running out-of-core solution) Objective Function (Minimize MASS ) = 5.22512E-03 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 9.00000E-001 Mass = 5.22512E-003 Subcase Compliance Epsilon 1 3.182106E+03 -2.217261E-08 2 3.090020E+01 -2.901012E-06 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 5.225E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 6.391E+00 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 6.381E+00 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- ITERATION 1 Objective Function (Minimize MASS ) = 4.96654E-03 % change = -4.95 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 6.00000E-001 Mass = 4.96654E-003 Subcase Compliance Epsilon 1 3.676331E+03 6.763454E-08 2 3.617831E+01 1.425096E-06 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 4.967E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 7.380E+00 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 7.372E+00 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- ITERATION 2 Objective Function (Minimize MASS ) = 4.70796E-03 % change = -5.21 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 3.00000E-001 Mass = 4.70796E-003 Subcase Compliance Epsilon 1 4.818794E+03 -5.075117E-08 2 4.668579E+01 7.748733E-07 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 4.708E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 9.668E+00 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 9.661E+00 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- ITERATION 3 Objective Function (Minimize MASS ) = 4.62177E-03 % change = -1.83 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 2.00000E-001 Mass = 4.62177E-003 Subcase Compliance Epsilon 1 5.707012E+03 -4.180833E-08 2 5.412942E+01 -1.809032E-06 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 4.622E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 1.145E+01 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 1.144E+01 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- COMPOSITE MANUFACTURING CONSTRAINTS ---------------------------------------------------------------------------- User-ID Constraint Information Status Max Avg Pct Type Bound Group Elem Viol. Viol. Viol. ---------------------------------------------------------------------------- 1 PLYTHK LOWER 4 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 5 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 6 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 7 ALL Active 0.0 0.0 0.0 ---------------------------------------------------------------------------- ITERATION 4 the 1st satisfied convergence ratio = 0.0000E+00 Objective Function (Minimize MASS ) = 4.62177E-03 % change = 0.00 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 2.00000E-001 Mass = 4.62177E-003 Subcase Compliance Epsilon 1 5.707012E+03 -5.735292E-08 2 5.412942E+01 -1.093063E-06 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 4.622E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 1.145E+01 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 1.144E+01 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- COMPOSITE MANUFACTURING CONSTRAINTS ---------------------------------------------------------------------------- User-ID Constraint Information Status Max Avg Pct Type Bound Group Elem Viol. Viol. Viol. ---------------------------------------------------------------------------- 1 PLYTHK LOWER 4 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 5 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 6 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 7 ALL Active 0.0 0.0 0.0 ---------------------------------------------------------------------------- ITERATION 5 the 2nd satisfied convergence ratio = 0.0000E+00 Objective Function (Minimize MASS ) = 4.62177E-03 % change = 0.00 Maximum Constraint Violation % = 0.00000E+00 Design Volume Fraction = 2.00000E-001 Mass = 4.62177E-003 Subcase Compliance Epsilon 1 5.707012E+03 -4.016066E-08 2 5.412944E+01 -5.919218E-06 Note : Epsilon = Residual Strain Energy Ratio. RETAINED RESPONSES TABLE ------------------------------------------------------------------------------------- Response Type Response Subcase Grid/ DOF/ Response Objective Viol. User-ID Label /RANDPS Element/ Comp Value Reference/ % /Model MID/PID/ /Reg Constraint +Frqncy Mode No. Bound /Times ------------------------------------------------------------------------------------- 1 MASS Mass -- -- TOTL 4.622E-03 MIN 2 DISPL Displ_Bi 1 87362 TXYZ 1.145E+01 < 1.190E+01 0.0 2 DISPL Displ_Bi 1 87363 TXYZ 1.144E+01 < 1.190E+01 0.0 ------------------------------------------------------------------------------------- COMPOSITE MANUFACTURING CONSTRAINTS ---------------------------------------------------------------------------- User-ID Constraint Information Status Max Avg Pct Type Bound Group Elem Viol. Viol. Viol. ---------------------------------------------------------------------------- 1 PLYTHK LOWER 4 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 5 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 6 ALL Active 0.0 0.0 0.0 1 PLYTHK LOWER 7 ALL Active 0.0 0.0 0.0 ---------------------------------------------------------------------------- ************************************************************************ OPTIMIZATION HAS CONVERGED. FEASIBLE DESIGN (ALL CONSTRAINTS SATISFIED). ************************************************************************ RESOURCE USAGE INFORMATION -------------------------- MAXIMUM MEMORY USED 2603 MB MAXIMUM DISK SPACE USED 33356 MB ************************************************************************ ************************************************************************ COMPUTE TIME INFORMATION ------------------------ EXECUTION STARTED Mon Jul 02 12:25:49 2018 EXECUTION COMPLETED Mon Jul 02 13:12:33 2018 ELAPSED TIME 00:46:43 CPU TIME 00:35:57 ************************************************************************ ***** END OF REPORT ***** For Useful OptiStruct Tips and Tricks, go to the URL: http://www.altairhyperworks.com/tips.aspxThank you
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Hi Samraj,
The output looks fine. I think you should be able to view the results. Try to select the component and click apply and check again please. If possible please share the des.h3d file.
Thank you
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Hi @Samraj
Can you share the constraint details?
Can you try with compliance and volume or the mass fraction response as a constraint?
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Hello @Prakash Pagadala @Premanand Suryavanshi
Thank you very much for the input. And sincere apologies for writing back late.
I tried using 'volfrac' and it seemed to work fine atleast. Is it possible to use 'Compliance' option? I have two load cases (bending and torsion) and each has maximum displacement constraint. So i created two diff. response option (one for each) and cross referenced each to its constraint, where i included the upper limit for maximum displacement.
Thank you
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Altair Forum User said:
Is it possible to use 'Compliance' option? I have two load cases (bending and torsion) and each has maximum displacement constraint. So i created two diff. response option (one for each) and cross referenced each to its constraint, where i included the upper limit for maximum displacement.
could you please elaborate what you mean by using compliance?
Since you have two load cases you may want to include Weighted compliance instead of compliance and select both the load cases.
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Hello @Prakash Pagadala
I am adapting some changes to the model using 'Weighted compliance'. I managed to include max. displacement values under 'Responses'. When i tried to add them as 'Constraints',
there are upper and lower bound otpions. In my case i have two upper bound values for two diff. load cases. should i leave this (please see the attached picture) column blank?
<?xml version="1.0" encoding="UTF-8"?>
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You can have two displacement constraints (in the image you are using WCOMP response, instead use Displacement response) and refer relevant load case.
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Hello,
I am little bit confused here.
1. The method i tried ==> created two responses for static displacement (one for bending and other for torsion). I used the independent node for each load case (please see the attached picture). Then under dconstraints tab, i refer the created respinses to constraints and also define the upper bound. I repeated the same procedure for the second load case.
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Hi
@Samraj Yes, that should work, but be careful when specifying the upper/lower bounds.
If the displacement is in the negative direction, you have to use lower bound instead of upper bound.
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Hello,
Yes. the value for lower bound is default where as only upper bound values defined.
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Hello,
yes. the bending load acts in -z direction. But i chose total displacement under 'Response' and included the upper bound value in positive. Is the approach correct?
Thank you
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Altair Forum User said:
yes. the bending load acts in -z direction. But i chose total displacement under 'Response' and included the upper bound value in positive. Is the approach correct?
Yeah,
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Great. Thank you
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Please keep the results, findings posted to us
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Hello,
I have a doubt. I have some optimization results. In the same folder, when i opened the subcase(s1.h3d) file, the maximum displacement value is more than what i had set as upperbound.
In this case, the maximum displacement i had set for bending was 12mm and the static analysis for final iteration shows 13mm. It is wrong. Just in case, i am now running '.....sizing.fem' file a static anaylsis.
Thank you
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Hello @Prakash Pagadala
Apparently, running a static analysis on '...sizing.fem' file produces results where the upper bound conditions are met. I tried to run a shuffle setup (idea from Skateboard tutorial).
- I changed the upperbound values of all the varibles under 'Design Variable' index.
- included some values for 'TMANUF' for the optimized plies.
- Changed to 'SZTOSH' under Output card.
I get the following error!
*** ERROR # 1814 *** VOLFRAC response on DRESP1 card 1 is not applied to a topology or free-size domain.Could you please help me fix this issue?
Thanks
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HI,
Volfrac can be used in Topology or freesize but not in size optimization problems.
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Hello,
Thank you for your response. I will look into the model again.
A bit irrelevant topic. I couldnt choose the outer most layer of solid elements of a component by using select 'by face' option. could you please let me know how its done?
Thank you
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Hi,
Never miind. have found a thread related to it.
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