爆炸载荷下埋地管线动力学分析数值模拟

 埋地管线的设计规范通常仅考虑管内介质、管边地质条件、环境条件、埋设方式和深度,而未考虑在土中爆炸的冲击载荷作用下埋地管线的安全性。本文利用有限元软件ANSYS/LS-DYNA,运用非线性动力学的基本理论和算法,选取适当的材料以及本构关系,对炸药在土中爆炸情形下埋地管线的动力学响应问题进行3维数值模拟。对比分析了不同装药量和爆心距对埋地管线损伤的不同作用,并对正对爆心管线界面上各节点受力进行了分析。结果表明,当炸药在浅土层中爆炸,炸药用量对管线的影响更为突出;同时也得出埋地管线在受到爆炸冲击载荷时,正对爆心截面上受到较大的轴向拉应力作用,且其作用可以看作瞬态受力过程。

Dynamic Analysis of Buried Pipelines Under Blast Loads with Numerical Simulation Method

The medium inside the pipe, the buried way and depth, the geological and environmental conditions were always paid much attention in design codes of buried pipeline, with the influence of blast loads being ignored. Actually, more and more pipes containing combustible materials are buried under the ground, once one of them blows-up, the blast loads would certainly influence others. In this paper, dynamic response of buried pipeline under blast loads in shallow soil was stimulated by ANSYNS/LS-DYNA FEM, a 3D numerical simulation software with the basic theory and algorithm of nonlinear dynamics. The influence of amount of explosive charge and distance to explosion center to buried pipe were comparatively studied with three groups of simulation. The radial stresses of different directions were also studied to find the weakest point. The results showed amount of explosive charge and distance to explosion center both influenced the dynamic response of buried pipe. The larger the amount of charge and closer to explosion center, the bigger the stress of buried pipe suffered. Comparatively, the amount of explosive charge played a more important role. Radial stresses analyses also implied that the biggest stress presented on the farthest point right under the explosion center and the broken of buried pipe reflected to tensile stress.