An analysis of stress uniformity in split Hopkinson bar test specimens
An analysis of stress uniformity in split Hopkinson bar test specimens
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DOI：
10.1016/j.ijimpeng.2003.09.002
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发表时间：
2005-02
影响因子：
5.1
通讯作者：
L. Yang;V. Shim
中科院分区：
文献类型：
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作者：
L. Yang;V. Shim
试样应力均匀假设是劈裂霍普金森杆（SHB）试验技术的基础。基于一维波特性法，对SHB法动态试验试样的应力均匀度进行了检验。建立了达到应力平衡所需的持续时间tb（或弹性波从试样的一端到另一端的传递次数），并与试样的相对机械阻抗β有关。在入射脉冲的上升沿对这一时间持续时间的影响也进行了研究，结果似乎表明，在试样中实现应力均匀性的最短时间要求入射脉冲具有特定的轮廓。本研究的结果为评估实验数据的有效性提供了指导。
The assumption of uniform stress in a test specimen is fundamental to the split Hopkinson bar (SHB) test technique. Based on the method of characteristics for one-dimensional waves, the degree of stress uniformity in specimens tested dynamically by the SHB method is examined. The time duration tb(or number of transits n an elastic wave makes from one end to the other of a specimen) required to attain stress equilibrium is established and related to the relative mechanical impedance β of the specimen. The effects of the rising edge in the incident pulse on this time duration are also studied and the results appear to indicate that the shortest time to achieve uniformity of stress in a specimen requires the incident pulse to have a specific profile. The results of this study provide guidelines to assess the validity of experimental data.