Compliance increase in the optimization
Hello,
I have been performing an optimization of carbon fiber monocoque. I set up the compliance as an objective to minimize to maximize the stiffness.
However, I have realized that compliance increase as the optimization progresses. I have checked the tutorials of optimization and the same happened. Should this value not be decreased?
Thank you
Answers
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what is your optimization setup??
Just check if your design constraints are not violated from the beginning.
Objective being Minimize means achieving the least possible WHILE RESPECTING CONSTRAINTS.
Not necessarily minimize will reduce your objective, if your constraint are not respected in the initial iteration.
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Yes, constraint violation is 0 in freesize and also in size optimization. Moreover at the end of the simulation appear the message: Feasible design (all constraints satisfied) what let me think the process is correct.
Is this output value what you refer with design constraint violating?
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do you have the .out file of the model that you see this happening??
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Yes, I have it, I have checked it there
I attached both files, freesize and size .out
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from freesize .out, there's a decrease, AS THE CONSTRAINTS ARE OK.
Iter 0
Objective Function (Minimize WCOMP) = 2.31275E+05
Iter 12
Objective Function (Minimize WCOMP) = 8.63265E+04 % change = -0.44
For Size, there's an increase AS THE CONSTRAINT HAS 9.4% VIOLATION:
Iter 0
Objective Function (Minimize WCOMP) = 1.03702E+05
Maximum Constraint Violation % = 0.93882E+01Iter 6
Objective Function (Minimize WCOMP) = 3.51606E+05 % change = 0.00
Maximum Constraint Violation % = 0.00000E+000 -
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
------------------------------------------------------------------------------------
2 WCOMP Wcomp -- -- -- 1.037E+05 MIN
1 MASS Mass -- -- TOTL 2.665E+01 < 2.436E+01 9.4 V
------------------------------------------------------------------------------------0 -
Thank you for the clarification, now I understand the concept
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Altair Employee