中文摘要：

为分析大质量破片对多层盖板炸药冲击起爆阈值的影响因素,采用SPH和 FEM相结合的方法开展了不同盖 板厚度和不同盖板间隔情况对起爆阈值影响的数值模拟.在此基础上,采用二级轻气炮作为加载手段,进行了大 质量钨合金破片冲击不同盖板及间隙情况下炸药冲击起爆试验研究,获得了起爆阈值.数值模拟与试验结果相一致,表明采用SPH与 FEM相结合的方法可以较好地模拟此类问题.通过拟合得到了大质量破片冲击起爆阈值速 度与冲击角度之间的经验关系式.分析结果表明,大质量破片冲击产生的大量二次破片对起爆阈值速度和起爆廷迟时间具有较大的影响.

英文摘要：

In order to investigate the influence factor of large-mass fragments on shock initiation, the smoothed particle hydrodynamics （ SPH ） and finite element method （ FEM） was combined, and the influence of different thinckness and different spacing of cover plates on initiation threshold was numerically simulated. The two-stage gas gun was applied, and the experiment of large-mass tungsten fragments impacting explosive was carried out. The critical initiation velocity was obtained. The simulation results are consistent with experimental results, and the SPH/FEM coupling method can be applied to analyze the velocity shock initiation problem. The correlations between critical initiation velocity and oblique impact angle were obtained by data fitting. Results show that the secondary fragments deriving from tungsten fragments have an important effect on the initiation velocity and the initiation delay- time.