基于混凝土试件SHPB实验的波形特征分析

Waveform features of split Hopkinson pressure bar tests of concrete specimen

为了研究混凝土分离式霍普金森压杆(SHPB)实验中的波形特征,结合Shaper技术进行了混凝土试件的大尺寸(Φ120mm×100mm)SHPB实验。分别分析了不同应变率下波形曲线上的一些典型特征点,揭示并解释了混凝土类脆性材料反射波"双峰"现象和反射波尾出现"压缩波段"的现象,同时分析了混凝土试件的塑性承载能力。研究结果表明,反射波尾的"压缩波段"现象及混凝土试件的"可持续"塑性承载能力均会随着加载速度的增加而消失,而反射波"双峰"现象是混凝土类脆性材料特有的性质,随着加载速度的增加反而逐渐明显。

To study the waveform features of concrete specimen in split Hopkinson pressure bar（SHPB） tests, large dimension （Ф120 mm × 100 mm） SHPB,tests of concrete specimen were conducted with pulse shaping technique（Shaper）. The typical feature points on the waveform curves under different loading rates were analyzed. According to the experiment, the ＂ double-peak＂ phenomenon of reflection wave in the SHPB tests of concrete-like materials was revealed and interpreted, and the ＂compression wave＂ phenomenon occurs in the tail of reflection wave under relatively lower strain rates. Further more, the plastic carrying capacity was also studied. The result shows that ＂compression wave＂ phenomenon and ＂sustainable＂ plastic carrying capacity will vanish with the increasing loading rate. On the contrary, the ＂double-peak＂ phenomenon, which is considered to be the specific property possessed by concrete-like materials, will become more apparent with the increasing loading rate.