Nonlinear Analysis of a thin composite laminate under large deformation

Dear Support Community,

I am currently working on the analysis of a highly deformed composite laminate. A very thin composite laminate sheet (ca. 0,4 mm) is 'clamped' (all DOFs constrained) at one end bent around 180° to form a 'c-shape' at the other. I am using the non-linear quasi-static solution option in OptiStruct, the composite part is made up of HEX8-elements with PCOMPLS property. When running the analysis the results (e.g bending moment (SPCF)) are by far stiffer than the predicted results. That got me wondering: Does OptiStruct regard the nonlinear behaviour of composite materials at high levels of strain (and therefore large displacements). I mean, does it take into account, that the moduli of the material behave nonlinear for very thin composites and very high levels of strain? I had a look into the OptiStruct help. It says there that 'classical lamination theory is used to calculate effective stiffness and mass density of the composite shell'. This is some information, but doesn't really answer my questions.

As always I would be very grateful for any helpful advice given.

Kind regards,

cfuser