身管内壁裂纹扩展特性及剩余寿命研究

火炮发射过程中身管内膛环境十分恶劣,经过一定射击发数后内膛往往出现不同程度裂纹,影响身管寿命及发射安全性。采用有限元软件建立了包含膛线及不同位置初始裂纹的身管有限元模型,基于线弹性断裂力学理论研究了膛压、弹带摩擦力、自紧残余应力等载荷作用下身管内壁不同位置初始裂纹的扩展特性,得到了影响身管疲劳裂纹扩展寿命的危险因素为身管内壁阴线纵向裂纹,基于疲劳裂纹扩展理论,以临界断裂韧度为失效判据,获得了无镀层身管在包含不同数量初始裂纹时的剩余寿命。研究对于火炮身管的发射安全性评估、寿命预测及寿命提升研究具有重要的参考价值。

Study on Crack Propagation Characteristics and Remaining Life of Gun Barrel Inner Wall

In the process of gun launching,the environment inside the barrel is so bad that the crack may appear in the inner wall after a certain number of shots,which will reduce the gun barrel life and affect launching safety.By using a FEM software program,the FEM model of a rifled barrel is established,in which initial cracks at different locations are considered.Based on the linear elastic fracture theory,the characteristics of propagation of the initial cracks at different positions on the gun barrel′s inner wall are studied considering the effects of chamber pressure,band friction and auto-frettage resi-dual stress.It is found that he risk factor determining the fatigue crack propagation life of the barrel is the longitudinal cracks on rifling grooves.Based on the fatigue crack propagation theory,the residual life of uncoated barrels with different numbers of initial cracks is obtained by using the critical fracture toughness as the failure criterion.This study has important reference value for gun barrel launch safety evaluation,life prediction and life promotion.