RPC材料冲击加载下的横向惯性和应变率效应

对3种钢纤维含量活性粉末混凝土(RPC)的冲击压缩性能进行了实验研究和数值模拟.为消除SHPB(Split Hopkinson Pressure Bar)冲击实验中的高频弥散和实现近似恒应变率加载,实验过程中采用了波形整形技术.考虑到RPC材料具有静水压力效应,其冲击加载下动态强度的提高实际是应变率效应和横向惯性造成的静水压力效应共同作用的结果.为了将二者加以区分,采用数值模拟结合静态围压实验确定材料的横向惯性效应,在此基础上,RPC材料的真实应变率效应被实验确定.

Effect of Lateral Inertia and Strain Rate for RPCs Under Impact Loading

The dynamic compressive properties of three types of reactive powder concretes(RPCs) were researched by experimental and numerical methods.The technique of pulse shaping was used to eliminate high-frequency-oscillation effect and achieve a nearly constant strain rate during the loading process.It is known that concrete-like materials are hydrostatic-stress-dependent,and the dynamic strength enhancement comes from both contributions of the hydrostatic stress and the strain rate.In order to differentiate these two factors,the effect of the lateral inertia was determined by a numerical method combing with quasi-static wall-pressure tests,and then the genuine strain-rate effect was experimentally determined.