A Simple Glassy Polymer Model

Abstract

This work presents a simple and robust material model, suitable for dynamic simulations of glassy polymers such as Polycarbonate. The new model reduces the complex stress/strain behavior and its dependence on strain rate and temperature to a simple set of characteristics. Utilizing a time–temperature superposition principle, these characteristics serve as input for a purely empirical fitting approach, which provides an accurate representation of the material behaviour over a wide range of strain rates and temperatures. Calibration data including failure at high rates is obtained using a split Hopkinson tension bar. To demonstrate the applicability of the new model, it is parameterized using high strain rate data and its simulation predictions compared to a gas gun impact experiment wherein a Polycarbonate plate is subjected to the impact of a steel sphere at temperatures between 23–80 °C and 56–75 m/s.