高抗冲聚苯乙烯的应变率敏感性及粘塑性本构关系

对高抗冲聚苯乙烯（HIPS）在应变跨越10^-4-10^1量级的范围内的拉伸力学性能作了实验研究,实验结果显示HPIS是一种应变率敏感的材料,其拉伸力学性能对应率敏感程度可分为高中低三个区域,在此基础上讨论了这类材料的粘塑性本构关系。

THE STRAIN RATE SENSITIVITY AND VISCOPLASTICITY CONSTITUTIVE RELATION OF HIGH IMPACT POLYSTYLENE

The strain rate sensitivity of the mechanical property of high impact polystylene(HIPS) was studied by tensile tests, and the orders of magnitude of the strain rate when testing are from 10 -4 to 10 1. The result of the tests shows that HIPS is sensitive to strain rate, its sensitivity can be divided into three areas: the high sensitive area that the orders of magnitude of the strain rate are below 10 -2; the medium one that the strain rate is in 10 -1; and the lower one that the strain rates are above 10 0. The mechanical property of HIPS is relating to strain rate when enter plastic state, appears obvious viscoplasticity. The constitutive relation can be expounded by a viscoplasticity theory based on overstress, and can be simulated by a simplified model which is composed of elastic element, plastic element and viscous element. The coefficients of the viscoplasticity constitutive equation are the functions of strain rate.