【摘要】 对于用常规SHPB试验确定的材料一维应力动态压缩特性,提出直接考证方法:把确定的试件材料的一维应力本构关系嵌入SHPB试验的全过程数值模拟,基本上再现了实验的反射波和透射波.把由一维准静态及动态压缩试验结果所确定的镁铝合金本构关系嵌入常规SHPB试验的全过程数值模拟,结果表明,采用SHPB试验经典分析所估算的应力、应变、应变率与试件典型差分微元在试验过程中所经受的应力、应变、应变率基本一致.本文对镁铝合金的脉冲造型SHPB试验进行了数值模拟,使试件有相当长的历时处于近乎常应变率状态.因此,对于应变率敏感材料的SHPB试验,入射波造型设计是有意义的.更多还原

【Abstract】 A direct verification method of a constitutive relation for material obtained by SHPB tests is presented: to question whether the numerical simulation of the SHPB test using the obtained constitutive law of the specimen represents the experimental reflected and transmitted pulse.Using the constitutive relation of the Mg-Al Alloy determined by quasi-static tests and SHPB tests and the developed one-dimensional simulation of the SHPB test,the numerically simulated stress,strain and strain rate of the typical Mg-Al Alloy element are consistent with the average stress,strain and strain rate of the specimen estimated by the classical SHPB analyses,respectively.A ramp incident pulse is applied in the simulated pulse shaped SHPB test for Mg-Al Alloy,and the numerical results show that the typical Mg-Al Alloy element deforms at a nearly constant strain rate over most of the duration of the test.Therefore,it is suggested that a pulse-shaping technique would be an essential modification of SHPB to determine compressive stress-strain data for strain-rate sensitive materials.更多还原