This study investigates the cracking mechanism of an elliptical bipolar linear-shaped charge blasting via theoretical analysis, experimentation, and numerical simulation. The results show that in the shaped charge blasting, due to the effect of the shaped jet in the direction of the shaped energy, a certain initial crack length is formed. In the action phase of the stress wave, the energy accumulation direction reduces the load required for crack initiation and propagation. The crack propagation length generated in the energy accumulation direction is greater than the nonenergy accumulation direction. The load value of the initial shock wave in the shaped energy direction is significantly greater, by about 1.64 times than the nonshaped energy direction, and the peak load acting time is earlier than the nonshaped energy direction. A large amount of impact explosion energy is consumed in the area close to the charged energy explosion due to the crushing area, regardless of the charged or noncharged energy direction. In the energy accumulation direction, the shock wave attenuation rate is faster in the near explosion area and the stress wave attenuation rate is slower in the mid and far areas of the explosion. The difference in the explosion load in the mid and far areas is small. In the nonconcentrated direction, owing to the reflected compression wave, the second stress peak appears in the nonconcentrated direction. However, its value is smaller than that of the initial shock wave peak.

中文翻译：

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椭圆双极线形装药爆破的开裂机理分析

本研究通过理论分析，实验和数值模拟研究了椭圆双极线形炸药的破裂机理。结果表明，在成形装药爆破中，由于成形射流沿成形能方向的作用，形成了一定的初始裂纹长度。在应力波的作用阶段，能量积累方向降低了裂纹萌生和扩展所需的载荷。在能量累积方向上产生的裂纹扩展长度大于非能量累积方向。初始冲击波在成形能量方向上的载荷值明显大于未成形能量方向的约1.64倍，并且峰值载荷作用时间早于非成形能量方向。不论带电或不带电的能量方向如何，由于破碎区域，在靠近带电能量爆炸的区域都会消耗大量的冲击爆炸能量。在能量积累方向上，爆炸附近区域的冲击波衰减率更快，爆炸中部和远端区域的应力波衰减率较慢。中远地区的爆炸载荷差很小。在非集中方向上，由于反射的压缩波，第二应力峰值出现在非集中方向上。但是，其值小于初始冲击波峰值的值。在能量积累方向上，爆炸附近区域的冲击波衰减率更快，爆炸中部和远端区域的应力波衰减率较慢。中远地区的爆炸载荷差很小。在非集中方向上，由于反射的压缩波，第二应力峰值出现在非集中方向上。但是，其值小于初始冲击波峰值的值。在能量积累方向上，爆炸附近区域的冲击波衰减率更快，爆炸中部和远端区域的应力波衰减率较慢。中远地区的爆炸载荷差很小。在非集中方向上，由于反射的压缩波，第二应力峰值出现在非集中方向上。但是，其值小于初始冲击波峰值的值。第二个应力峰值出现在非集中方向。但是，其值小于初始冲击波峰值的值。第二个应力峰值出现在非集中方向。但是，其值小于初始冲击波峰值的值。