高速破片在防雷舱结构中引起的冲击荷载的理论研究

Shock loading induced by high speed fragment in cabin near shipboard

运用一维平面波理论,研究大型高速破片在防雷舱结构中引起的冲击荷载,得到了初始冲击荷载的理论公式。与有限元计算结果进行比较,证明了理论公式的正确性。运用理论计算公式分析了破片参数对冲击荷载的影响,结果表明:破片速度与冲击荷载峰值成正比,速度越快,峰值越大;速度越慢,峰值越小。而破片速度对冲击荷载的衰减没有影响,即不同速度的破片在水中引起的冲击荷载具有相同的衰减规律。不同厚度破片引起的冲击荷载的具有相同的峰值,但有不同的作用时间。破片的越厚,荷载作用时间越长;破片越薄,荷载作用时间越短。最后基于理论分析确定了几何衰减的函数形式,采用数值试验数据进行回归分析,得到了冲击波的几何衰减系数。

Applying the one dimension plane wave theory, the shock loading induced by high speed large fragment in cabin near shipboard was studied. A theretieal formula of initial shock loading was attained and proved by comparing with the result of FEM. The influences of parameters of fragment on shock loading was analyzed based on the theoretical formula. The results show that the velocity of fragment is in direct ratio with the peak value of shock loading. The more rapidly fragment moves, the bigger the peak value. And the velocity of fragment has no influence upon decay of shock loading, namely, the shock loading of fragment with different velocity will decay according to a same mode. The shock loading induced by fragment with different thickness results in a same peak value, but different duration. The thicker the fragment, the longer the duration. Based on the theoretical analysis, the functional form of geometrical attenuation was established. By the regression analysis on the data of numerical test, the coefficient of geometrical attenuation of shock wave was got.