航空用有机玻璃(PMMA)的非线性热粘弹-塑性本构关系

 实验测定了航空用有机玻璃T=-40～40℃,ε_t=1.0×10_-4～1.0×10_-1s_-1范围内单轴压缩循环的应力-应变曲线。提出一种考虑温度和应变率效应的非线性粘弹性变形和塑性变形相耦合的本构关系,给出了完备的微分和积分形式的关系方程组,用于拟合各不同温度和应变率的实测曲线,获得了良好吻合的结果。

THE NON-LINEAR THERMOVISCOELASTIC-PLASTIC CONSTITUTIVE RELATIONS FOR AN AERONAUTICAL PMMA

The uniaxial-compresgion stress strain curves of loading-and-unloading cycle in the ranges of T= - 40-40℃ and ε_t = 1.0 × 10_-4-1.0×10_-1s_-1 for an aeropautical per-spex-PMMA liave been experimentally measured. A non-linear and rate-dependent thermoviscoelastic-plastic constitutive model, i. e. an activation dashpot which is used to consider the plastic deformation in series couple with on equivalent standard linear solid or an equivalent Maxwell body which is used to consider the viscoelastic deformation, is suggested. The effects of both temperature and strain rate can be considered in our model. The comprehensive constitutive relations both in differential and integral forms are worked out. While using these relations to fit the stress-strain curves measured experimentally, the agreement shows veasonably good with the correlation coefficients greater than 99%.