What Methodology Does OptiStruct Use for Topology Optimization

BUGRA

Hello, 

I need to undestand theoratical background of topology optimization by OptiStruct. One of the optistruct guide says it uses SIMP (Solid Isotropic Material with Penalty). On the other hand, One of the optistruct guide says it uses Gradient Based Method. 

When I check OPTMETH, options are as follows, MFD, SQP, DUAL, DUAL2, BIGOPT. Some of them are Gradient Based Methods. Therefore, I am confused which method is being used by OptiStruct.

Could you please share your opinions ?

Thanks

PaulAltair

SIMP (density method) is the default method for topology optimisation, you may also enable LEVELSET Levelset method in help for topology.

These methods are both concerned with the topology adjustment itself, i.e. whether the material in a given location/element is 'active' or not

The Gradient based method options (the OPTMETH you mention) are not concerned with topology optimisation (specifically), but apply to all optimisation methods, they are the mathematical approaches for the solver to determine whether a design iteration change (of any kind, topology, size, shape, etc) is improving/converging on an optimum solution. Gradient Based Methods in help