基于异常压力场的火炮身管断裂失效再现数值模拟

Numerical Simulation on Reappearance of Artillery Barrel Fracture Damage Under the Effect of Abnormal Gas Flow

针对某坦克炮实弹射击出现身管断裂失效的情况,采用问题再现、原因分析、计算分析和效果验证等研究方法,利用LS-DYNA程序流固耦合算法,以等量TNT爆轰产生的高压气体流场近似代替实际火药气体作用,采用基于显式积分的拉格朗日-欧拉耦合算法解决流体与固体的耦合,建立了高压气体与身管之间相互作用的数值模拟,解决了流体形变引起的计算困难问题。引入Johnson-Cook塑性模型以及断裂失效模型描述身管材料动力学响应,在预置初始裂纹的情况下对身管在异常内压下的动力学响应进行了数值计算及分析。数值模拟结果较好地描述了身管材料在异常压力作用下的断裂失效机理,再现了身管发生撕裂损伤破坏的过程,为火炮使用安全性以及故障分析提供了参考。

Aiming at the occurrence of barrel fracture of a tank gun when firing,the research methods of problem reproduction,reason analysis,calculation analysis and effect verification were adopted.By using the LS-DYNA program fluid-solid coupling algorithm,the high-pressure gas flow generated by the equivalent TNT explosion approximately substituted for the actual gunpowder gas.By using the Lagrangian-Euler coupling algorithm based on explicit integration,the problem of the fluid-solid coupling was solved,and the numerical model of the interaction of the high pressure gas and barrel was set up.The problems of calculation caused by the fluid deformation were solved.The Johnson-Cook plastic and damage evolution model was introduced to describe the dynamic response of barrel material.In the case of presetting initial crack,the dynamic response of the barrel under abnormal internal pressure was numerically analyzed.The results of numerical simulation well described the fracture failure mechanism and reappeared the barrel tearing process.The study offers reference for the safety and fault analysis.