混凝土SHPB束杆装置冲击实验的数值仿真

Numerical simulation of concrete impact test using split Hopkinson pressure bundled bars device

利用Ansys/Ls-dyna有限元软件模拟不同打击气压下混凝土SHPB束杆实验,对实验装置模型进行了简化;采用梯形应力脉冲载荷,模拟得到了实验中试件的应力-应变曲线。结果显示:模拟结果与实验结果吻合较好,验证了该方案的可行性;同时试样应力峰值随打击气压增大而增大。对不同幅值梯形应力脉冲加载下的SHPB束杆装置和单杆装置实验进行数值仿真,研究表明:束杆装置中试样应力峰值比单杆装置小一些;随应力脉冲载荷幅值增大,束杆装置中试样应力峰值增长速度要高于单杆装置。

The numerical simulations of tests of the concrete bundled Hopkinson pressure bars under different fire pressures are studied by using the finite element software of ANSYS/Ls-dyna in this paper. The test device model is simplified, and the trapezoidal stress pulse loading is used. The above methods are verified by experiments. The stress-strain curves of specimens obtained from simulations are in good agreement with the experimental results. Peak stress is increased with the increase of fire pressure. Comparative numerical simulation of impact test process of the SHPB bundled bars device and 74 single bar device are carried out. The results show that peak stress of specimens in bundled bars device are smaller than single bar ones, and with the increase of stress pulse amplitude, stress peak values increase faster than the single bar case.