Peng Xu, Renshu Yang, Yang Guo, Cheng Chen, Yuantong Zhang
Appl Opt. 2019 Dec 10;58(35):9718-9727. doi: 10.1364/AO.58.009718.
This study uses a cracked medium to study the interaction mechanism between blast waves and the precrack. The experimental results show that the compressive phase of the dilatational wave would cause the opened precrack to close with a negative sign of stress intensity factor $K_{\rm I}^d$KId, while the tensile phase of the dilatational wave attributes to the precrack opening and increases the crack velocity. However, the shear wave tends to make crack initiation at mixed-mode I/II fracturing by increasing the dynamic stress intensity factor $K_{\rm II}^d$KIId. As a dynamic crack approaches the precrack, the precrack initiated and finally formed an interlocking fracture shape between the precrack and dynamic crack. Besides, the shading effect of the precrack on blast waves is investigated numerically.
本研究采用含裂纹介质来研究爆炸波与预制裂纹之间的相互作用机理。实验结果表明，膨胀波的压缩阶段会使张开的预制裂纹闭合，应力强度因子$K_{\rm I}^d$为负，而膨胀波的拉伸阶段则导致预制裂纹张开并提高裂纹速度。然而，剪切波倾向于通过增加动态应力强度因子$K_{\rm II}^d$使裂纹在I/II混合型断裂模式下萌生。当动态裂纹接近预制裂纹时，预制裂纹开始扩展，最终在预制裂纹和动态裂纹之间形成互锁断裂形态。此外，还对预制裂纹对爆炸波的遮蔽效应进行了数值研究。
