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总览 评价 张瑞娟 ， 敬霖 ， 赵隆茂 * （ 太原理工大学，应用力学与生物医学工程研究所； ） 摘要： 本文利用大直径（74 mm）SHPB试验装置对水泥砂浆材料进行了动态性能实验研究。实验中采用了脉冲整形技术以改善实验精度，并对试件的不同位置采用应变片测
张瑞娟， 敬霖， 赵隆茂*
（
太原理工大学，应用力学与生物医学工程研究所； ）
摘要：
本文利用大直径（74 mm）SHPB试验装置对水泥砂浆材料进行了动态性能实验研究。实验中采用了脉冲整形技术以改善实验精度，并对试件的不同位置采用应变片测试了其轴向和周向的应变。实验研究结果发现：采用脉冲整形器在脆性材料动态实验中实现“恒应变率”变形具有较大的困难,如刻意追求“恒应变率”可能造成实验的动态特性过度“牺牲”，导致试件中的应变率达不到“转变应变率”。另外还发现：尽管在试件的几何尺寸设计上采取了消除横向惯性效应的措施，采用了脉冲整形器延长入射波的上升时间以保证试件中的变形均匀性，但其轴向应变并不相等，且仍然存在有非常大的径向应变，从而横向惯性效应对实验 精度造成不可忽略的影响。
关键词：
脆性材料；SHPB；实验研究；脉冲整形器；恒应变率
Zhang Ruijuan， Jing Lin， Zhao Longmao*
（
Institute of Applied Mechanics and Biomedical Engineering, Taiyuan University of Technology； ）
Abstract：
Dynamic properties of cement mortar materials was investigated by a large-diameter (74 mm) split Hopkinson pressure bar apparatus in this paper. Pulse shaping is used to improve experiment accuracy. Strain guage is pasted in the different place of specimens to measure its axial and radial strain.It is found that achieving “constant strain rate” deformation by pulse shaper is very difficult in dynamic experiment of brittle materials. If “constant strain rate”is seeked strictly, which will result in that dynamic properties of experiment will be reduced largely and strain rate in the specimens may not reach transition strain rate. In addition, it is also found that even though eliminating inertia-induced radial confinement effect is measured by designing geometry dimension of specimens and pulse shaper is used to prolong the rise-time of the incident pulse to ensure deformation equilibrium in the specimens, but axial strain in different place of specimens is not equal and very large radial strain still exist. Therefore, non-ignorable effect for experiment accuracy is induced by inertia-induced radial confinement effect.
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