How to use optistruct for optimization

Hi

I am new to FEM and just started using Hypermesh and its solvers. I realized that radioss and optistruct are basically the same but optistruct is also used for optimization. How exactly is a model optimized using optistruct and what optimization are we talking about. Any help will be appreciated

Thanks

Bharat

maybe if you could check the tutorials you will see how it works. basically you define some optimization targets and it solves the analysis several times to match those design targets, when it matches it stops solving and then you can evaluate the results with those desing targets. e.g. changing some normal modes through optimizing the mass.