超空泡射弹动力稳定性的非概率可靠性分析

Non-probabilistic Reliability Analysis for Supercavitating Projectile Based on Dynamic Stability

超空泡射弹水下高速运动时,前端所受轴向扰动载荷非常大。考虑到扰动载荷的不确定性,有必要对超空泡射弹进行动力稳定性的可靠性分析。建立超空泡射弹截锥形结构的动力偏微分方程,并将其转化为二阶常微分Mathieu型参数振动方程,利用Bolotin方法对其动力稳定性进行数值计算,给出射弹结构动力稳定性的安全余量方程。分别分析了不同弹体杆径比、不同射弹航行速度以及不同弹体长度3种情况对超空泡射弹动力稳定性的影响,在此基础上进行了结构的非概率可靠性分析,得到了结构的非概率可靠度,通过算例说明该方法的有效性。

Aimed at the axial disturbed load to the head of supercavitating projectile at high speed motion underwater, its indefiniteness was considered, and the structure reliability of supercavitating projectile was analyzed on the basis of dynamic stability. The partial differential dynamic equation of the projectile＇s cut-off-cone structure was established, then it was transformed to a second-order ordinary differential Mathieu equation, and the numerical calculation for the dynamic stability of supercavitating structure was ＂performed with Bolotin method, finally, the dynamic stability safety margin equations of supercavitating structure was given. The iniluences of length-diameter ratio, velocity and length of supercavitating projec- tile on the dynamic stability were analyzed. Based on those, the structural non-probabilistic reliability was analyzed and obtained, the effectiveness of the method was demonstrated by using some examples.