摘要:
为了实现对钨合金弹丸侵彻靶板过程的精确表征,分别采用FEM、SPG、SPH、FE-SPH自适应数值仿真方法,对钨合金弹丸侵彻Q235A钢靶开展了数值仿真计算,对比了四种数值仿真方法在描述弹丸侵彻穿靶后,弹丸剩余速度、靶板穿孔孔径以及弹丸穿靶后二次破片的生成方面的优势和不足。结果表明:在描述弹丸剩余速度方面,由于FEM方法在材料失效时基于单元侵蚀算法,因此FEM方法以及FE-SPH自适应方法严格依赖于失效准则以及失效参数的选择,而SPG方法无需调整失效参数就可以得到相对准确的结果;在描述靶板穿孔孔径上,FEM以及FE-SPH自适应方法具有精确的物质边界,可以精确刻画穿孔形貌特征,但不同失效准则下的靶板穿孔直径相差较大,SPG方法对失效参数不敏感,可以精确表征靶板的穿孔直径;在弹丸穿靶后二次破片的生成方面,FE-SPH自适应以及SPH方法均能对二次破片进行表征,FE-SPH自适应方法可以直接获取大质量破片信息,但相比于SPH方法,求解效率低下。
Abstract:
In order to achieve accurate characterization of the process of tungsten alloy projectile penetrating the target, Finite Element Method (FEM), Smoothed Particle Galerkin (SPG), Smoothed Particle Hydrodynamics (SPH) and FE-SPH adaptive numerical simulation methods were used respectively to carry out numerical simulation calculation of tungsten alloy projectile penetrating Q235A steel target. The advantages and disadvantages of four numerical simulation methods in describing the residual velocity of the projectile, the perforation diameter of the target plate and the formation of secondary fragments after the projectile penetrates the target are compared. The results show that in terms of describing the residual velocity of the projectile, FEM method and FE-SPH adaptive method are strictly dependent on the selection of failure criteria and failure parameters because FEM method is based on the element erosion algorithm when dealing with the material failure problem. The SPG method is based on the bond fracture model when simulating material failure. The bond can be broken to simulate material failure without deleting SPG particles, and it is insensitive to failure parameters, so relatively accurate results can be obtained without adjusting failure parameters. In terms of describing the perforation diameter of the target plate, FEM and FE-SPH adaptive methods have accurate material boundaries and can accurately characterize the perforation morphology of the target plate, but the perforation diameter of the target plate varies greatly under different failure criteria. The SPH method is inferior to the SPG method in characterizing the perforation diameter of the target plate, and because the SPG method is not sensitive to the failure parameters, it can also accurately characterize the perforation diameter of the target plate. In terms of secondary fragment generation, FEM method can only generate large fragments, but not small fragments. The SPG method can characterize large and small fragments, but cannot output SPG particles as fragment information. Both FE-SPH adaptive method and SPH method can characterize large and small fragments, and the FE-SPH adaptive method can directly obtain the information of large fragments, but compared with the SPH method, the calculation efficiency is low.