In this paper, the crack propagation behavior of a polymethyl methacrylate plate with double holes under explosive load is investigated. The propagation process of the explosion crack is recorded using a new digital laser dynamic caustics system, in which a high-speed camera and the explosion loading are employed. Firstly, the interaction process between the explosion stress wave and the empty hole reflected stress wave is analyzed using caustics. Moreover, the deflection law of the explosion crack is discussed. Secondly, the relationship between the propagation distance, velocity, stress intensity factor of the explosion crack tip, and the distance between the two holes is analyzed. Finally, the explosion process is analyzed using numerical simulations. It is concluded that the evolution law of the explosion stress wave in during the simulation process is similar to the caustics diagram. Lastly, the time-varying law of the stress between the double holes is obtained.

本文研究了爆炸载荷作用下双孔聚甲基丙烯酸甲酯板的裂纹扩展行为。使用高速摄像机和爆炸载荷的新型数字激光动态焦散系统记录爆炸裂纹的扩展过程。首先，利用焦散分析爆炸应力波与空孔反射应力波的相互作用过程。此外，还讨论了爆炸裂纹的挠度规律。其次，分析了爆炸裂纹尖端的传播距离、速度、应力强度因子与两孔间距的关系。最后，对爆炸过程进行了数值模拟分析。得出模拟过程中爆炸应力波的演化规律与焦散图相似。最后，得到了双孔间应力的时变规律。