对常规的霍普金森压杆装置进行改进,使其可以应用于干性砂土试样的冲击试验。针对干砂开展冲击试验,得到应变率在102~103 s-1范围内稳定的入射波、反射波和透射波的波形图,并用橡胶膜作为波形整形器以获得更明显的透射波信号。结果表明:在较高应变率荷载作用下干砂没有明显的应变率效应;对于等厚度砂土试样,应变率随着加载气压的增大而增大,且增大趋势明显;在同等加载条件下应变率随着砂土试样厚度的增大而减小。
A split Hopkinson pressure bar(SHPB)was appropriately modified to study the dynamic behavior of dry sand.A stable,incident,reflective,and transmitted waves under the strain rates of 102~103 s-1 were obtained and a rubber membrane barrier was found to facilitate transmission of the pressure wave.The results showed that strain rate effect can be ignored for dry sand at high strain rate.For sand samples of the same thickness,the strain rates were increased as the load increased.The experimental results suggested an upward trend in strain rate.Under the identical loading conditions,as the thickness of sand samples was increased,the resulting strain rate decreased.