A Thermo-Mechanical Constitutive Model of Glassy Shape Memory Polymers

Abstract

Glassy shape memory polymer materials are applied successfully in biomedical fields due to their large recovery deformation, excellent biocompatibility and unique biodegradability. To predict the thermo-mechanical behavior of glassy shape memory polymers in biomedical devices accurately, a reasonably three-dimensional thermo-mechanical constitutive model must be established firstly. A one-dimensional linear-elastic constitutive model proposed by Tobushi et. al. (1997) was extended to capture the loading level dependent degradation of shape memory effect by introducing new nonlinear evolution equations with threshold values. Comparisons between experiments and simulations were carried to validate the extended model. Simulation results agree with experiments well, especially for the high loading levels.