SHPB混凝土实验中试件尺寸的影响(英文)

Influence of Specimen Size in SHPB Tests on Concrete

分离式霍普金森压杆(SHPB)实验常被用来获得混凝土类材料的动态压缩强度,所得数据对建立本构方程有重要作用,因此需要对其进行正确解释或分析。利用最新的混凝土材料模型研究了SHPB实验中试件尺寸的影响。藉由混凝土试件的体积考虑动态尺寸效应的影响,并提出了一个计算由于惯性(约束)效应引起的动态增强因子的新经验公式。结果表明:新经验公式与不同尺寸混凝土的SHPB模拟结果吻合得很好,且惯性(约束)效应引起的动态增强因子随着试件尺寸的增大而增大。

The split Hopkinson pressure bar（SHPB）tests are often conducted to obtain the dynamic compressive strengths of concrete-like materials which need to be interpreted or analyzed correctly as these data are very important for the construction of reliable constitutive equations used in numerical simulations.In the present work,a numerical study is performed on the influence of specimen size on concrete in SHPB tests using a rate-independent material model.A new empirical equation for the dynamic increase factor due to inertia（confinement）effect is also proposed which took account of specimen size effect through its volume.It is shown that the empirical formula agrees well with the numerical results for the SHPB tests on concrete with different specimen sizes,and the dynamic increase factor due to inertia（confinement）effect increases with the increase of specimen size.