高应变率大变形下的聚丙烯/尼龙共混高聚物损伤型本构特性

对两种采用不同相容剂的聚丙烯（PP）和尼龙（PA）共混高聚物材料在大变形下的粘弹性力学行为进行研究，着重考察应变率效应和损伤的演化，从而分析不同的界面分子设计对共混体系材料宏观性能的作用。在准静态及冲击实验研究的基础上，基于ZWT非线性粘弹性模型，并结合了遗传算法，分别得到了能有效描述两种共混高聚物大变形阶段计及损伤的非线性粘弹性本构关系。两种材料在不同加载条件下表现出明显不一致的性能，原因在于其损伤演化的率相关性，且两种材料的大变形机制存在一定的差别，能用ZWT方程进行描述的范围也不一样。

The constitutive behavior of PP/PA polymer blends taking account of damage evolution at high strain rate and large deformation

By using the nonlinear ZWT model and the genetic algorithm method and taking the rate-dependent effects and damage evolution into account, experiments in the quasi-static and impact loading were performed to study the visco-elastic mechanical behaviors of PP/PA polymer blends with two types of interface modifier in the large deformation condition. The nonlinear visco-elastic constitutive equations considering damage evolution for these materials were obtained respectively. Results show that  the deformation mechanisms of polymer blends with two different compatibilizers in the large deformation condition are different due to the visco-plastic effect, and that the visco-plastic deformation influences the polymer blend with TPE-g as compatilizer more greatly than the polymer blend with PP-g-MAH as compatilizer, and the strain range, in which the ZWT model can be applicable, is ε<15% for the former, while for the latter it is ε<24%.