爆炸荷载下缺陷介质裂纹扩展规律数值分析研究

利用爆炸加载数字激光动态焦散线试验系统,同时借助ABAQUS有限元分析中内聚力模型数值计算方法,研究了爆炸应力波作用下缺陷介质裂纹扩展规律,并将试验结果与数值计算结果进行了对比。研究表明:在爆炸应力波作用下预制缺陷两端产生了两条翼裂纹A、B,扩展长度基本相同,方向垂直于预制缺陷。两条翼裂纹的扩展基本是对称的,只是在尾端发生轻微翘曲;翼裂纹扩展速度先增大至峰值又振荡减小,之后又增大至第二个较小的峰值,然后又减小,这种变化趋势和裂纹尖端应力强度因子KⅠ保持一致;扩展角β为85°时,计算结果较为接近试验,内聚力模型为动态裂纹扩展的研究提供了一种有效的方法。

Numerical Simulation Research of Crack Propagation in Media Containing Flaws under Explosive Load

The test system of digital laser dynamic caustics under explosive stress wave was used to study the law of crack propagation in media containing flaws under the explosive stress wave with CZM numerical methods in the ABAQUS finite element analysis,and comparison between the test results and numerical calculation results were also conducted. The results showed that two wing cracks A,B were generated at both ends of the prefabricated flaw under explosive stress wave;the extended length was basically similar and the direction was perpendicular to the prefabri-cated flaw. Crack propagation of the two wings was substantially symmetrical,just a little minor warping at the end. The velocity of wing crack showed the same trend with crack tip stress intensity factor KⅠ. When the extended angleβ is 85 °,the numerical calculation result is closer to the test;the cohesive model provided an effective method for the study of the dynamic crack propagation.