A constitutive model of thermoviscoelastic semicrystalline shape memory polymer considering viscous dissipation in the amorphous phase

Mathematical modeling has increasingly recognized as a powerful tool that could aid the understanding of shape memory behavior in semicrystalline shape memory polymer (SMP). Up to now, studies have not fully taken into account the viscous effect of the amorphous phase in the whole shape memory cycle, which causes a more realistic prediction of the SMP behavior. In this work, a constitutive thermoviscoelastic model was developed to predict the thermomechanical behavior of semicrystalline SMP. The simulated results of the proposed model for a typical uniaxial deformation were compared with the case having no dissipation effect, also with experimental data. The accuracy improvements in the results of the stress–strain trends together with fixing ratio and recovery ratio obtained from the modified model were significant. The results were in good agreement with the experimental data. The modified model revealed a real and more accurate trend by considering viscous dissipation.