Finite element analysis of mechanical behavior and thermal shrinkage of poly(ethylene-terephthalate) (PET) film in the glass transition temperature region

Abstract

Finite element analysis has been performed based on a mechanical model proposed here to interpret the experimental data of stress-strain curves and thermal shrinkage behavior of poly(ethylene terephthalate) (PET) films observed in the temperature region near the glass transition point. The proposed mechanical model consists of a parallel array of hyper-elastic element and plastic deformation element. The former element was introduced to explain the thermal shrinkage above the glass transition temperature and the latter element was required to explain the permanent strain detected for the oriented PET sample. The numerical calculation was performed to give a good reproduction of the experimental data on the basis of explicit finite element method. © 2012 The Japan Society of Mechanical Engineers.