基于弹塑性模型的某舰炮抽壳力仿真计算

Simulation Calculation of Shell Extraction Force for Naval Guns Based on Elastic-plastic Model

舰炮射击后药筒贴膛力对抽壳初速存在重要影响,贴膛过程药筒表现出弹塑性大变形特性,且沿口部至底部贴膛极不均匀,简化的二维模型及薄壁圆筒解析模型已经不能满足定量的分析需求。建立了基于弹塑性抽壳过程动力学仿真模型,采用Johnson-Cook本构模型描述药筒弹塑性大变形行为,通过仿真计算获取药筒及炮膛动态应力应变、接触力及摩擦力等参量,分析了药筒动态贴膛规律及受力特性。仿真结果表明,舰炮射击过程药筒经历贴闩、径向自由膨胀至贴膛、贴膛后与炮膛协同变形及回弹至平衡态四个阶段,平衡状态后抽壳阻力不再变化,保持在13320N左右,抽筒子作用于药筒后抽壳初速最高达到18.9m/s,该抽壳初速满足了舰炮高速连发的设计性能要求。

The loading force of the barrel after firing has an important effect on the initial velocity of the shell extraction.During the loading process,the barrel exhibits large elastic-plastic deformation,and the loading is very uneven from mouth to bottom.The simplified two-dimensional model and thin-walled cylinder analytical model can no longer meet the quantitative analysis needs.A dynamic simulation model based on the elastic-plastic extraction process was established,and Johnson-Cook constitutive model was used to describe the elastic-plastic large deformation behavior of the cartridge.Parameters such as dynamic stress and strain,contact force and friction force of the cartridge and gun bore were obtained through simulation calculation,and the dynamic loading law and force characteristics of the cartridge were analyzed.The simulation results show that during the firing process,the barrel of naval gun goes through four stages:bolt attaching,radial free expansion to bore attaching,co-deformation with bore after bore attaching,and rebound to the equilibrium state.After the equilibrium state,the resistance of shell extraction no longer changes and remains at about 13320N,and the muzzle velocity of shell extraction after the cylinder acting on the barrel reaches 18.9m/s.The muzzle velocity can meet the design performance requirements of high-speed continuous firing of naval guns.