单脉冲加载的Hopkinson压杆实验中预留缝隙确定方法的研究

Investigation of the Pre-fixed Gap in Single-Pulse Loading Technique of Hopkinson Pressure Bars

在传统Hopkinson压杆实验中,反射拉伸波在入射杆的撞击端反射形成压缩波,导致实验过程中对试样进行了多次加载,单脉冲加载的Hopkinson压杆实验技术解决了该问题。详细总结了单脉冲加载的Hopkinson压杆实验技术原理,给出了法兰盘与质量块间预留缝隙的计算方法,分析了预留缝隙不同大小对实验结果的影响。建立了一套单脉冲加载的Hopkinson压杆实验装置,并利用高速摄影验证了实验技术的可靠性。

In conventional Split Hopkinson Pressure Bars（SHPB） experiments, the tension pulse reflected from the sample back into the incident bar will travel to the free end of the bar and then will reflect back to the sample as compression wave. As a result, the sample is loaded many times. The single-pulse loading technique of the Hopkinson pressure bars can solve the problem. This paper presents the basic principle of the single-pulse loading technique of Hopkinson pressure bars. The way to calculate the pre-fixed gap between the transfer flange and reaction mass is given. The experimental results with various pre-fixed gap are obtained. A device of the single-pulse loading technique is set up. High speed photography is applied to confirm the validation of the technique. Both the photoes and the experimental strain waves show that sample was loaded only once.