Experimental Research on Velocity Distribution and Energy Partitionning of Fragments Produced by Catastrophic Disruption

在400 - 900米/秒的速度范围内进行了立方叶蜡石的撞击实验。碎片的运动由高速电影摄影机记录。三维速度从分析电影。得到的结果是：1.其他研究小组提出的破片速度对破片质量的依赖性没有得到证实.单次运行的平均碎片速度与无量纲冲击应力（NDIS）参数成正比。NDIS参数是由目标强度归一化的目标后表面处的冲击波压力。单次运行中的碎片速度与d的-4/5次方成比例，其中d是从炮点到碎片初始位置的距离。所有实验的破片速度都与破片初始位置处的冲击波压力P的1/4次方成正比，这些关系不是直接从NDIS的定义中推导出来的。然而，这些结果表明，为了确定撞击碎裂现象的标度律，有必要阐明撞击产生的峰值压力、高压区的大小和形状以及压力的衰减率。它还表明，NDIS是一个合适的参数的碎片速度以及尺寸分布。

Impact experiments of cubic pyrophyllites were performed in a velocity range of 400 to 900 m/sec. Motions of fragments were recorded by a high-speed movie camera. Three-dimensional velocities were determined from analyses of films. obtained results are :1. Fragment velocity dependence on the fragment mass proposed by other research groups was not observed.2. Average of fragment velocities of a single run is proportional to the nondimensional impact stress (NDIS) parameter. The NDIS parameter is the shock wave pressure at the rear surface of a target normalized by the target strength.3. Fragment velocities in a single run are proportional to d to the power -4/5, where d is the distance from the shot point to the initial position of the fragment.4. Fragment velocities of all the experiments are proportional P to the power 1/4, where P is the shock wave pressure at the initial position of the fragment.These relations are not derived from the definition of NDIS straightforwardly. However, these results indicated that it is necessary to elucidate the peak pressure generated by an impact, the size and shape of high-pressure region, and the decay rate of the pressure for the definition of the scaling law of impact fragmentation phenomena. It is also shown that the NDIS is an appropriate parameter for the fragment velocities as well as size distributions.