【摘要】 为有效测量试件中的应力、应变及应变率,Hopkinson拉伸试验(TSHB)必须作优化分析,所进行的数值模拟涉及试件与杆件等连接对于实验结果的影响.为减小上升前沿、惯性效应且使试件处于一维应力及均匀应力与应变状态,优化的试件具有一定的长度与形状要求.对于高导无氧铜,由准静态试验及不同应变率与温度的优化TSHB试验得到一系列应力-应变曲线,并被拟合确定J-C及Z-A型动态本构模型.利用所确定的动态本构模型数值计算的反射与透射的应变在一定程度上与实验结果一致.文中强调指出,必须采用全过程数值模拟,对TSHB试验进行优化设计,并且对所确定的试件动态本构模型进行代入校核,再现实验结果.更多还原

【Abstract】 Optimization on Hopkinson tensile bar tests(HTBS) should be conducted in advance for the effective measure of stress,strain and strain rate in specimen.Numerical simulation carried out involves the effects of interconnecting linkage between specimen and bars on experimental data.To reduce the rising edge,inertia effect and to make the specimen in a one-dimensional stress and uniform stress and strain state,the optimal specimen should satisfy a few length and shape requirements.For oxygen-free high conductivity(OFHC) copper,the stress-strain curves are obtained at first under both quasi-static tension tests and the optimized HTBS tests for different strain rates and temperatures,and then,the J-C and Z-A type dynamic constitutive relations are determined through fitting.The reflection and transmission strains computed with the obtained constitutive relations of OFHC copper are consistent with the experimental data to a certain extent.It is indicated that HTBS tests should be optimized and the determined constitutive models of specimen should be checked by using the numerical simulations of HTBS tests.更多还原