身管镀层界面失效分析及寿命预测研究

目的 研究热压耦合作用下身管镀层的界面失效机理，预测身管寿命。方法 建立镀层界面剪切失效、界面弯曲失效和界面裂纹扩展失效3种失效模型，并给出失效准则。以某小口径步枪身管为研究对象，基于完整冷却周期的身管温度场数值模拟结果，计算这3种失效在相同射击条件下的临界失效长厚比，并对结果进行对比分析，确定身管镀层的主要界面失效方式。结合镀层的界面失效机理和低周疲劳损伤累计理论，建立基于镀层界面疲劳损伤累积的身管寿命预测模型，对该小口径步枪身管的寿命进行预测。结果 临界失效长厚比计算结果表明，界面剪切失效是身管镀层的主要失效方式。身管寿命预测结果与寿命试验结果相比，误差小于2%。结论 界面剪切失效是身管镀层的主要失效方式，基于镀层界面疲劳损伤累积的身管寿命预测方法是可行的。

Analysis of Interface Failure and Life Prediction of Coating in Gun Barrel

This paper aims to study the mechanism of interface failure mechanism of coating in gun barrel and predict the service life of gun barrel .Three interface failure models (interface shear failure, interface bending failure and interface crack growth failure) of coating in gun barrel are built, and the failure criterion is given correspondingly. Then a small caliber gun barrel is employed as study object and the critical failure L/h ratio of different failure models during firing process are calculated based on temperature field simulation result. By comparison of the calculation results, thus, the main interface failure way of coating in gun barrel is confirmed. Going forward, a life prediction method of gun barrel based on coating interface fatigue damage accumulation is proposed by comprehensive application of the theory of fatigue damage accumulation and the theory of coating interface failure mechanism. The life prediction model of gun barrel is built and the life of this small caliber gun barrel is predicted. In conclusion, the calculation results indicate that shear failure is the main interface failure way, and the differences between service life prediction results and life test results are less than 2%, which verifies that the prediction method proposed in this paper is feasible.