混凝土材料的SHPB试验及动态性能分析

通过SHPB试验研究了混凝土材料的动态性能。考虑到SHPB装置存在的诸如应力应变不均匀、大尺寸产生的应力波弥散等缺陷，试验中选用了φ37mm的SHPB研究了混凝土材料在中应变率时的动态响应，并以试验数据为依据，分别阐述了混凝土材料的应变率效应、骨料对混凝土材料的动态响应影响及混凝土材料的应变硬化和应变软化现象。结果表明：混凝土在一定应变率范围内随着应变率的增加，其动态一静态抗压强度比呈对数线增加，且动态响应由硬化向软化过渡；骨料的抑制作用是混凝土材料表现出弹塑性特征的关键因素，也使得SHPB试验测得的混凝土动态响应曲线呈现振荡。

SHPB Experiment and Dynamic Properties of Concrete

By means of SHPB experiment the dynamic properties of concrete are researched. With such disadvantage as the ununiformity of stress or strain and the dispersion in wave propagation, the 37 nun-diameter SHPB is chosen to study the dynamic response of concrete at the medium strain rate. Based on the experimental data, the strain-rate effect, the influence of aggregate on dynamic response of concrete and the phenomena of strain hardening and strain softening are analyzed respectively. The results show that, with the increase of rate of strain, the raof dynamic - static compressive strength of the concrete increases in the logrithmic curve within certain rate of strain range, and the dynamic response of concrete transforms from hardening to softening. The derepression of aggregates is the key factor that the concrete has the elastoplastic behavior, and also the main reason that the dynamic response curves vibrate during the SHPB experiment.