Anisotropic creep analysis of fiber reinforced load point support structures for thermoplastic sandwich panels

The present contribution is concerned with a numerical analysis of creep in load point support structures for sandwich panels made from different fiber reinforced thermoplastic materials. Whereas the face sheets consist of laminates of unidirectional carbon fiber reinforced plies, the support structures for the load points consist of discontinuously long fiber reinforced thermoplastics manufactured in a compression molding process. The sandwich core is a thermoplastic foam. For the numerical creep analysis of such structures under long-term loading, an anisotropic viscoelastic material model is formulated. In different versions, the model is applicable either to unreinforced thermoplastics, or to thermoplastics with discontinuous or continuous fiber reinforcement. The material model is implemented into a finite element system. The model is validated against an experimental data base on both, coupon and structural level.