基于唐志平等提出的剪切波跟踪技术(SWT),对钢纤维增强水泥砂浆进行了冲击速度40m/s~270m/s倾斜角为0~20°的斜撞击试验.研究结果表明,在此冲击速度下,材料处于损伤状态和由损伤状态向孔洞崩塌过渡阶段.此结果与聚丙烯纤维增强水泥砂浆的实验结果进行对比,发现钢纤维体积含量为0.5%时,对压缩性能的增强效果并不明显,但相应的剪切波速明显增加;当钢纤维体积含量为1%时对压缩性能和剪切波速均有较大的提高.由于钢纤维与水泥砂浆基体的强度相差太大,剪切强度有一定的改善,但数据较离散.同时通过对剪切结果分析表明,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.
Based on the shear wave tracing technique (SWT) proposed by Tang ZP, series of experiments, which includes oblique planar impact with inclination angles of 0-20 degree and impact loading velocity ranging from 40m/s to 270m/s are carded out in the present paper to investigate the responses of steel fiber reinforced cement (SFCEM) subject to impact loading. Experimental results show that the material is at the stage of damage or the transition stage from damage to void collapse under these impact velocities. Compared with the experimental results of Polypropylene micro-fiber reinforced cement (FCEM), conclusion can be drawn that the transversal wave velocity of the composites with 0.5 percent in volume of steel fiber is evidently increased, but not the compression resistant capability; while both are evidently increased for the composites with 1.0 percent in volume of steel fiber. However, since the strength of steel fiber is greatly higher than that of the cement matrix, the improved amplitude of shear strength for SFCEM is distributed randomly. On the analyses of shear strength, it can be concluded that the transversal wave, especially the unloading transversal wave, is important for the dynamic damage investigation of brittle materials.