ESLM: Stopping Criteria

Altair Forum User

I have used OptiStruct nonlinear-response optimization via Equivalent Static Load Method (ESLM) extensively in my research but would like to know more regarding its stopping criteria of the outer loop i.e. 

 

How are convergence criteria defined in order to stop the ESLM (besides ESLMAX max.no. of iteraitons reached)?

 

I know OBJTOL is used in the inner loop (linear static opt. loop), but not sure whether the outer nonlinear-response loop deploys the same criteria. I have not found this info in the User’s Guide.

 

 

I appreciate your kind support in this matter.

 

Mr.ESLM

Altair Forum User

Answer from Altair Development Engineer:

 

'We basically check the number of outer loops w/o any change or improvement in objective/constraint. This is consistent with regular OS optimization.

 

For example, if the number of outer loop w/o any change (see below tolerance) => 2, then convergence is satisfied.

 

Tolerance for maximum constraint violation change – default = 5.0E-3

Tolerance for objective function value change – default = 5.0E-3'