某大口径机枪内膛损伤对弹头挤进过程的影响研究

Research on the Influence of Damaged Bore of a Large Caliber Machine Gun on Bullet Engraving Progress

为研究大口径机枪枪管寿命过程中内膛损伤对弹头动态挤进过程的影响,分析影响枪管寿命的关键因素,在进行大量射击试验获得枪管内膛损伤发展规律基础上,建立了不同寿命阶段含内膛损伤枪管的精确有限元模型。采用Fortran子程序的方式实现了内弹道过程与显式有限元方法的迭代数值求解,获得了弹头挤进过程中表面形貌及运动姿态随内膛损伤发展的变化数据。对比数值模拟结果与试验数据验证了弹-枪耦合模型的准确性。仿真结果表明:内膛损伤导致的弹头挤进过程中,质心偏移量和弹头摆动角的增加、表面形貌及气动力参数的改变,以及由于导转侧损伤较严重引起的弹头所受导转力和转速下降等3个因素是导致弹头外弹道飞行稳定性降低及枪管寿终的主要原因。研究结果为进一步研究枪管寿终机理,提高枪管寿命具有一定的参考意义。

In order to study the influence of damaged bore on the dynamic engraving process and find the key factors significantly influencing a barrel life,the accurate finite element analysis(FEA)models of large caliber machine gun barrels in different life periods are established based on the evolution rule of bore damage obtained through a large number of firing tests.The data of bullet surface morphology and moving posture during engraving process are obtained through numerical simulation which combines the interior ballistic process and the explicit finite element method through Fortran subroutines.The coupled model of bullet and gun barrel is proved to be effective by comparing the calculated results with experimental results.The simulated results show that three major influencing factors,such as the increase in the offset of bullet mass center and the swing angle of bullet,the variation in bullet surface topography and aerodynamic parameters,and the reduction in the driving side force and rotational velocity of bullet due to the severely damaged driving side,result in the reduction in exterior ballistic flight stability and the barrel life end.