火炮身管阳线损伤机理分析

Anlysis of Rifling Land Damage Mechanism of Gun Barrel

某大口径火炮实弹射击中,身管阳线起始段出现双侧棱边断裂损伤,为揭示阳线损伤故障原因,进而采取措施避免损伤复发,基于动态非线性有限元方法,建立了弹丸身管耦合系统非线性有限元分析模型,综合考虑了弹丸装填不到位、初始装填角、非均匀摩擦、弹炮间隙多因素对弹丸身管耦合系统动力响应的影响。在此基础上,研究了弹丸装填不到位造成的冲击加载对身管材料动态性能的效应。结果表明,弹丸挤进过程在阳线起始段引起的等效应力已接近身管材料动态屈服极限,同时,弹丸装填不到位使弹带与身管撞击力提高约3.7倍、身管材料动态断裂韧性降低35.6%,最终导致阳线起始段局部双侧棱边的断裂损伤。验证试验复现了阳线损伤现象,确认了阳线损伤机理理论分析的正确性。

In the live firing of a large caliber gun,a fracture damage was found on the bilateral edge of the lands in an initial segment of barrel. In order to reveal the fault reason and take measure to avoid the recurrence of this fault,a nonlinear finite element analysis model of coupling system formed by barrel and projectile is established based on dynamic nonlinear finite element method. Several influence factors,such as inaccurate bullet loading,initial loading angel,inhomogeneous friction and gap between barrel and bullet,are taken into account synthetically for dynamic response analysis of the coupling system. The influence of impact loading caused by the inaccurate bullet loading on the dynamic behavior of barrel material is investigated. The results show that the equivalent stress caused by projectile in the engraving process of bullet in the initial segment of barrel is already close to the yield limit of barrel material,the impact force between the bearing band and barrel is increasesd by 3. 7 times due to the inaccurate loading,and the dynamic fracture toughness of the barrel material is decreased by 35. 6%,resulting in a fracture damage on the bilateral edge of lands in the initial segment of barrel. The phenomenon of rifling land damage is recurred in the test of living firing.