TOWARD A NEW PHENOMENOLOGICAL FLOW RULE FOR ORIENTATIONALLY HARDENING GLASSY POLYMERS

摘要

A new yield surface is proposed herein, and the behavior of its associated flow rule is explored. This anisotropic dow rule exhibits solutions which follow fairly well the orientational hardening behavior of glassy polymers. Specifically, solutions obeying the flow rule are calculated for various orthotropic loading histories, and comparisons are made to experimental data for polycarbonate. While these solutions have been restricted to rate independent plasticity in this initial study, the comparisons to experiment are encouraging. Additionally, the framework given herein provides a rational means for describing phenomenologically deformation induced elastic stiffening and deformation induced elastic anisotropy in these materials. [References: 20]