Abstract

Many features of dynamic fracture caused by shock-wave action are most pronounced under spalling conditions, i.e., when an intense wave pulse is reflected from a free boundary. Therefore, such material tests are one of the main ways to study the fracture processes occurring in a solid under ultrafast dynamic stress. Nevertheless, the geometrical characteristics of the fracture zone formed under spalling conditions are relatively little studied. It was experimentally established that the qualitative appearance of such a multiple fracture region is characterized by strong instability and depends on the parameters of the applied pulse, such as the rate of increase and decrease in stress, amplitude, and duration. Based on an analysis of a number of experimental results, it will be shown below that the unstable behavior of the fracture zone formed in the spalling conditions observed in the experiments can be explained and predicted using the structural-temporal approach based on the concept of incubation fracture time.

中文翻译：

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剥落条件下断裂带的临界和几何特征的不稳定性

摘要

由冲击波作用引起的动态断裂的许多特征在剥落条件下最为显着，即当自由边界反射了强烈的波脉冲时。因此，这种材料测试是研究固体在超快速动应力下发生断裂过程的主要方法之一。然而，在剥落条件下形成的断裂带的几何特征还很少研究。实验确定，这种多重断裂区域的定性外观具有很强的不稳定性，并且取决于所施加脉冲的参数，例如应力的增加和减少的速率，幅度和持续时间。根据对许多实验结果的分析，