Characteristics of the stress pulse generated by impact of a hollow striker on the flange of a split Hopkinson tension bar are investigated via an explicit finite element analysis. Design guidelines are extracted for the hollow striker and flange from the viewpoint of eliminating spurious waves located between the incident and reflected pulses. According to design guidelines, it is desirable to have a striker cross-sectional area the same as that of the flange. It is also desirable to make the cross-sectional area of the striker (flange) the same as that of the bar. As for the flange length, it is recommended to be comparable to the diameter of the bar. The magnitude and duration of the primary stress pulse are consistent with the results of a one-dimensional analysis even when spurious waves are present; meanwhile, overly long spurious waves should be avoided to eliminate their superposition with the reflected pulse. Spurious waves appear when general impedance of the striker is higher than the bar. The origin of spurious waves is a series of step-wise residual pulses generated by multiple cycles of striker impact that make the striker keep compressing the flange after the first cycle of impact. Step-wise residual pulses appear in two forms (continuous waves and discrete waves) in spurious waves due to the secondary impacts during the entrance process of step-wise residual pulses to the flange. The consequences of spurious waves in the use of split Hopkinson tension bars are discussed.

中文翻译：

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分体式霍普金森拉杆的撞针和传递法兰的设计指南和杂波的起源

通过显式有限元分析，研究了空心撞针撞击分裂式霍普金森拉杆法兰时产生的应力脉冲特性。从消除入射脉冲和反射脉冲之间的杂散波的角度出发，提取了空心撞针和法兰的设计指南。根据设计指南，最好使撞针的横截面积与法兰的横截面积相同。还希望使撞针（法兰）的横截面积与杆的横截面积相同。至于法兰长度，建议与棒材直径相当。即使存在杂散波，主应力脉冲的幅度和持续时间也与一维分析的结果一致；同时，应避免过长的杂散波，以消除它们与反射脉冲的叠加。当击球手的总阻抗高于横杆时，就会出现杂散波。杂散波的起源是由多次撞击循环产生的一系列步进式残余脉冲，使撞击器在第一次撞击循环后继续压缩法兰。由于阶跃残余脉冲进入法兰过程中的二次冲击，阶跃残余脉冲以两种形式（连续波和离散波）出现在杂散波中。讨论了使用分裂式霍普金森拉杆时杂散波的后果。杂散波的起源是由多次撞击循环产生的一系列步进式残余脉冲，使撞击器在第一次撞击循环后继续压缩法兰。由于阶跃残余脉冲进入法兰过程中的二次冲击，阶跃残余脉冲以两种形式（连续波和离散波）出现在杂散波中。讨论了使用分裂式霍普金森拉杆时杂散波的后果。杂散波的起源是由多次撞击循环产生的一系列步进式残余脉冲，使撞击器在第一次撞击循环后继续压缩法兰。由于阶跃残余脉冲进入法兰过程中的二次冲击，阶跃残余脉冲以两种形式（连续波和离散波）出现在杂散波中。讨论了使用分裂式霍普金森拉杆时杂散波的后果。由于阶跃残余脉冲进入法兰过程中的二次冲击，阶跃残余脉冲以两种形式（连续波和离散波）出现在杂散波中。讨论了使用分裂式霍普金森拉杆时杂散波的后果。由于阶跃残余脉冲进入法兰过程中的二次冲击，阶跃残余脉冲以两种形式（连续波和离散波）出现在杂散波中。讨论了使用分裂式霍普金森拉杆时杂散波的后果。