A Macro-Damaged Viscoelastoplastic Model for Thermomechanical and Rate-Dependent Behavior of Glassy Polymers

Abstract

he primary objective of this paper is to develop a macro-damaged viscoelastoplastic constitutive model to describe large deformation mechanical behavior for glassy polymers at various kinds of experimental conditions. First of all, quasi-static and dynamic tension and compression tests were carried out to obtain stress–strain responses over wide range of rates and temperatures for two glassy polymeric materials, polymethylmethacrylate and polycarbonate. Then a phenomenological macroscopic damage model, covering effects of strain rates, temperatures, and effective strain, is incorporated into the constitutive model in the previous work. Furthermore, two distinct criteria are applied to predict the damage evolution affected by strain rate and temperature at elastic phase and plastic phase, respectively. The validations of the novel developed damaged model are made by the better matches with the testing data compared with the original undamaged model, and excellent agreements with the experimental result in all cases.