采用改进的分离式Hopkinson拉杆测试技术对低强度材料进行动态拉伸.该装置采用铝杆作为透射杆,并且透射杆采用半导体应变片.针对一种芳纶绸布材料,进行了试样两端应力平衡、实验速度、半导体应变片与电阻应变片测量的验证,获得了不同速度下被测材料的本构曲线,并通过高速照相机清楚地观察了试样的整个破坏过程.实验结果表明,设计的实验方法行之有效。
An improved split Hopkinson bar was used for testing the dynamic tensile behaviour of low strength materials.This device included an aluminum transmitted bar and the semiconductor gages to capture the weak strain signal.For material of aramid fiber silk,the stress equilibrium on both sides of specimen as well as the test speed was verified; a comparison between the measurements from semiconductor strain gauge and from resistance strain gauge was made; the stress-strain curves of tested material under various impact velocities were obtained; the failure process of specimen was captured by a high-speed camera.The experimental results show that the design of the experiment method is feasible.