12.7 mm 弹侵彻不同强度钢靶的数值模拟

A 12.7-mm projectile may remain intact or be broken during penetrating into steel targets with different strengths. However, previous simulations were limited to simulating a single situation. To break this limitation, the numerical simulation methods of the 12.7-mm projectile penetration into steel targets were studied, leading to a projectile-target model which was capable of simulating both the intact and broken cases. In the intact projectile case, the ballistic tests were implemented to study the dynamic behavior of the 12.7-mm projectile penetrating into the 603 steel targets. Two different modeling algorithms based on the finite element method (FEM) and the smooth particle hydrodynamics particles (SPH) method, respectively, were compared with the experimental results. Then the influences of finite element and particle sizes on the numerical results were studied to establish the numerical model to simulate the intact projectile case. Furthermore, the established model was applied to simulate the broken projectile case by changing the target material and the element sizes. The numerical results were then compared with the experimental results. The numerical study shows that the projectile and target should be discretized using the FEM and SPH, respectively, for simulating the intact case. Meanwhile, a large ratio between the finite element mesh size and the SPH particle spacing should be used, such as 5.3. Otherwise, an abnormal numerical deformation may occur around the projectile head, which is inconsistent with the experimental result. This model can also be used to simulate the broken projectile case, as verified with the experimental results. However, the large ratio between the finite element mesh size and the SPH particle spacing leads to numerical problems and abort of simulations. To overcome this difficulty, an FEM/SPH coupled projectile-target model is proposed, in which the projectile was discretized using coarse meshes close to the surface and fine meshes in the core region. Numerical results show that the proposed projectile-target model can be used to simulate the penetration process no matter the projectile remains intact or broken.