聚丙烯短微纤维增强水泥冲击特性研究

基于唐志平等提出的剪切波跟踪技术(SWT),对聚丙烯短微纤维增强水泥(FCEM)和素水泥(CEM)进行了冲击速度76～506m/s、倾斜角为10的斜撞击试验。研究结果表明,两种材料的Hugoniot冲击绝热线均有四个明显的临界点A、B、C、D,分别对应材料的Hugoniot弹性限、剪切卸载波(S-)消失、孔洞崩塌点和颗粒材料的再压缩点。其中临界点B,在过去的研究工作中尚未被揭示,只有采用剪切波跟踪技术对S-波进行跟踪测量,才能最终确定。对剪切强度的分析结果表明,采用剪切波,尤其是卸载剪切波来探测脆性材料内部动态损伤非常有效。

Experimental investigation on dynamic properties of the polypropylene micro-fiber reinforced cement (FCEM) under impact loading

Based on the shear wave tracing technique (SWT) proposed by Z.P.Tang, a series of experiments including oblique planar impact of inclination angle 10 degree, impact loading velocity ranging from 75m/s to 506m/s for FCEM and from 74m/s to 484m/s for CEM, have been carried out to investigate the responses of polypropylene micro-fiber reinforced cement to impact loading. Experimental results show that there exist four critical points A, B, C and D along the p-V Hugoniot curve. They correspond to the HEL of the material, the shear strength limit and the transition from damage state to failure state, void collapse and the shock compression, respectively. The critical point B is difficult to be identified and has not been reported before. However, it can be clearly distinguished with the SWT technique. According to the analyses of shear strength, it can be concluded that the transversal waves, especially the unloading ones, are of importance to the dynamic damage detection in brittle materials.