Composite size optimization

Hi,

I am trying to do a size optimization of a composite plate. My plate is composed of 8 small plates. I have run 2 models with the same parameters except that one is based on PLY card: each plate has 4 plies (0/45/90/-45) with a STACK (SMEAR). The other model is based on PCOMP, one per plate with the same plies and the SMEAR card.

Can you explain me why the results of the size optimizations are different?

Thanks,

Ludov

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