Explanation for very large maximum constraint violation % in the first iteration
Greetings,
I am performing a free-size optimization (iteration summary given below) and trying to understand the explanation behind maximum constraint violation %. So far the following is clear:
- If constraint violation > 1% : status is V (violated)
- If constraint violation < 1% : status is A (Active)
- Large constraint violation % could mean that the constraint is too tight and that the problem itself is ill-defined.
- the difference between regular and soft convergence is understood as well
Problem definition: The thickness of an insert is defined to be the DV. Two stress constraints are defined. The objective is a stress minmax formulation.
Question: I am unable to figure out whether the large constraint violation % implies a critical issue. If yes, how does one rectify the problem?
Iteration Subcase Variable Grid/Elem ID Value
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0 1 MaxDisp 4712_Y 5.96215e-05
0 0 ObjFun:Min(Max)EQATN 0 4.50698e+07
0 0 MaxConstrViol(%) 0 125.349
1 1 MaxDisp 5566_Y 5.67884e-05
1 0 ObjFun:Min(Max)EQATN 0 3.80622e+07
1 0 MaxConstrViol(%) 0 90.3111
2 1 MaxDisp 5566_Y 5.72058e-05
2 0 ObjFun:Min(Max)EQATN 0 3.54572e+07
2 0 MaxConstrViol(%) 0 77.286
3 1 MaxDisp 5566_Y 5.86367e-05
3 0 ObjFun:Min(Max)EQATN 0 3.52875e+07
3 0 MaxConstrViol(%) 0 76.4375
4 1 MaxDisp 5566_Y 5.95676e-05
4 0 ObjFun:Min(Max)EQATN 0 3.51522e+07
4 0 MaxConstrViol(%) 0 75.7608
5 1 MaxDisp 5566_Y 6.00593e-05
5 0 ObjFun:Min(Max)EQATN 0 3.50283e+07
5 0 MaxConstrViol(%) 0 75.1417
6 1 MaxDisp 5566_Y 6.04046e-05
6 0 ObjFun:Min(Max)EQATN 0 3.49025e+07
6 0 MaxConstrViol(%) 0 74.5125
Answers
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Hi
why did you define constraints 'stress' simultaneously objective 'stress' ?
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Hi Tinh,
Does such a definition pose a conflict? Do you also have any comments on the large constraint violation %?
In this case, the two constraints defined are the allowable stresses in the adhesive and the adherend. We would, however, like the stresses developed to be far below the allowables. The objective has been set to minimize stresses in the adhesive only.
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What is that %? are you sure it is % stress violation?
Did you create displacement constraint anywhere?
if you set objective is minimum stress and has no constraint, I will create a big size part!
I am not sure whether OS also does.
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There is no displacement constraint: The objective is to minimize stress is adhesive. The constraint set is maximum stress in the insert.
Altair Forum User said:What is that %?
I am trying to figure this out too. What constraint violation & actually means?
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If you dont figure out. Make a simple problem to check it
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