SHPB入射波相似律与整形技术的试验与数值研究

Experimental and numerical study on the incident pulse similarity law and pulse shaping technique in SHPB test

利用量纲分析理论研究了使用整形器的分离式霍普金森压杆(SHPB)试验入射波形是否满足几何相似律的问题。通过试验和数值仿真对其结果进行验证;基于直径为14.5 mm的SHPB装置,分析了整形器和撞击杆参数对入射波形的两个重要拐点的影响规律,得到入射波T_(1)和T_(2)拐点的无量纲表达式。结果表明:当撞击杆的速度保持不变,整形器直径与杆的直径同比放大或缩小时,考虑整形器的SHPB装置满足严格的几何相似律;入射波T_(1)拐点主要与整形器的直径和厚度以及撞击杆的速度有关,而入射波T_(2)拐点主要受整形器的厚度和撞击杆的速度影响,撞击杆长度只是影响入射波的持续时间,对入射波形上升沿阶段没有影响。

Based on the dimensional analysis theory,whether the incident pulse of the split Hopkinson pressure bar(SHPB)test with a pulse shaper satisfies the geometric similarity law was studied.The results were verified by experiments and numerical simulations.The effects of the pulse shaper and impact bar parameters on the two important inflection points of the incident pulse were analyzed based on a SHPB device with the bar of 14.5 mm diameter.Moreover,the dimensionless expressions of the incident pulse at T_(1) and T_(2) inflection points were obtained.The results show that when the diameters of the pulse shaper and striker bar are enlarged or shrunk in the same proportion with the impact bar velocity kepping constant,the SHPB device with the pulse shaper conforms to the geometric similarity law.The inflexion point T_(1) is mainly related to the pulse shaper diameter,its thickness and the striker bar velocity,while the inflection point T_(2) is mainly affected by the pulse shaper thickness and the striker bar velocity.The striker bar length only effects the incident pulse duration,but has no effect on the rise edge stage of the incident pulse.