Predicting polyurethane shape memory behaviors in stress-controlled situations using a viscoelastic model

As an outstanding class in smart materials of particular interest, shape memory polymers (SMPs) and their composites are drawing more and more attentions due to their potential applications in fields like biomedical and spacecraft industry. In this paper, shape memory behaviors of polyurethane (PU) in stress-controlled situations are simulated on the basis of the generalized Maxwell model and the time-temperature superposition principle. The free recovery cycles under three different imposed stresses and the influence on shape memory behaviors caused by changing heating rate are discussed. As the results reveal, the generalized Maxwell model can be used to describe the PU shape memory performance, and the shape recovery temperature increases with the increase of heating rate.