Nonlinear Finite Element Modelling of Thermo-Visco-Plastic Styrene and Polyurethane Shape Memory Polymer Foams

This paper presents nonlinear finite element (FE) models to predict time- and temperature-dependent responses of shape memory polymer (SMP) foams in the large deformation regime. For first time, an A SMP foam constitutive model is implemented ABAQUS FE package with aid a VUMAT subroutine thermo-visco-plastic behaviors. phenomenological reformulated adopting multiplicative decomposition gradient into thermal mechanical parts considering visco-plastic matrix glass microsphere inclusions. The stress split scheme considered by Maxwell parallel hyper-elastic rubbery spring. Eyring dashpot used for modelling isotropic resistance local molecular rearrangement such as chain rotation. viscous flow rule adopted prescribe shear viscosity stress. An evolution also athermal strengths simulate macroscopic post-yield strain-softening behavior. In order validate accuracy well solution procedure, numerical results are compared experimental Styrene Polyurethane at different temperatures under strain rates. show that introduced procedure capable capturing major phenomena observed experiments elastic elastic-plastic behaviors, softening plateau regime, densification.