A NON-LINEAR VISCOELASTIC-PLASTIC CONSTITUTIVE MODEL FOR GLASSY POLYMER PMMA
玻璃态高聚物PMMA的非线性粘弹-塑性本构方程

This paper discusses the expressions of macroscopic mechanics for theuniaxial-compression stress-strain behaviour of glassy polymer PMMA, i.e. the constitutive relations, according to the experimental data. A non-linear viscoelastic- plastic constitutive model composed of an activation dashpot by taking into account of the strain-hardening effect coupl in series with a standard linear solid or a Maxwell body is suggested. The comprehensive constitutive equations both in differential and integral forms are provided. When these equations are used to fit to the experimental stress- strain curves of loading-and-unloading cycle, the results show that the agreements are reasonably good.