多点同步起爆条件下环形射流成型及侵彻过程的数值模拟

Numerical Simulation on Formation and Penetration Processes of the Annular Jet With Multi-Points Synchronous Explosive Circuit

运用显式动力学有限元软件LS-DYNA,对环向多点同步起爆条件下装药爆轰波的传播规律、环形药形罩在爆轰波作用下成型过程及环形射流对靶板的侵彻效应进行了数值模拟,分析了起爆点数对侵彻能力的影响。研究结果表明:环向多点同步起爆条件下,爆轰波通过相互碰撞形成统一的波浪形爆轰波前沿,爆轰波前沿到达药形罩顶端的时间沿环向并不同步,压力大小也不一致。环形射流不仅头部和尾部之间存在速度梯度,沿环向也存在一定的速度差异,难以保持形状。环形射流对靶板的破坏形式主要为塑性扩孔或塑性扩孔+剪切冲塞,形成的圆形弹孔孔径与环形药型罩对称面直径相当。环形射流的侵彻能力随起爆点数的增加而增大,当起爆点数大于10时,侵彻深度增大幅度会明显减小。

By using the explicit dynamic finite element analysis code LS-DYNA,the propagation of detonation waves,the formation process of the annular shaped liner under the action of detonation wave,and the penetration effect of the annular jet on the target with multi-point synchronous explosive circuit are numerically simulated.Meanwhile,the effect of the number of detonation points on the penetration ability is analyzed.The results show that under the condition of circular multi-point detonation,a uniform wave-like detonation front is formed through the interaction of the detonation waves,and the time of detonation wave front reaches the top of the liner is not synchronous along the circumferential direction,and the pressure is not the same.The annular jet not only has velocity gradient between the head and tail,but also has a certain speed difference along the circumferential direction,thus the shape of the annular jet is difficult to maintain.The failure mode of the target is ductile hole enlargement or the combination of ductile hole enlargement and shear plugging,and the diameter of the circular hole is equivalent to that of the symmetric plane of the annular liner.The penetration ability of annular jet increases with the increase of the number of detonating points,but when the number of detonating points is greater than 10,the increase in penetration depth decreases significantly.