延性材料平面冲击波基本实验数值模拟的若干问题

ON SOME PROBLEMS IN NUMERICAL SIMULATIONS OF BASIC PLANAR SHOCK TESTS FOR DUCTILE MATERIALS

假设屈服强度正比于剪切模量,分别构建了四种强度模型,并用于数值模拟Ly12铝的平面冲击波试验的质点速度剖面以及钨合金的平面冲击波试验的锰铜计应力记录.研究发现,基于Steinberg等的屈服强度模型比较符合实验.还对平面冲击波试验的层裂现象进行了简化的数值模拟,其中,采用了该文作者所提出的一种基于空穴聚集的层裂模型,该模型的特点是分别引入了层裂过程的早期及后期应力松弛方程.

Four strength models are established in this paper by assuming a directly proportional dependence of yield strength upon shear modulus, and these models are applied to numerically simulate the profile of particle velocities of Ly12 aluminium under planar shock feats and the lateral stress in tungsten alloy recorded by the manganin gauge under the planar shock tests. It is found that the model based upon the Steinberg yield-strength is better agreement with the experimental data. Furthermore, the planar spalls occurring in planar shock tests of ductile metals are numerically simulated, too. using the previous moder on spall phenomena based on void coalescence preposed by us. The feature of that model is to introduce different stress-relaxation equatious, respectively, in the early and litter phases of planar spalls.