长杆弹撞击陶瓷靶的一种数值模拟方法

陶瓷材料具有高强度和低密度等特点，抗弹性能优越，被广泛用于各类装甲中。长杆弹撞击陶瓷靶时会发生径向流动、质量显著侵蚀而无明显侵彻的界面击溃现象，是陶瓷抗侵彻性能研究中具有重要研究价值的特殊现象。利用有限元软件AUTODYN建立了长杆弹撞击陶瓷靶的二维轴对称计算模型，采用Lagrange和光滑粒子流体动力学（smooth particle hydrodynamics, SPH）算法，模拟了柱形钨合金长杆弹撞击带盖板的碳化硅陶瓷，通过改变长杆弹的撞击速度，得到了界面击溃、驻留转侵彻和直接侵彻3个不同现象。讨论了不同建模算法、边界条件以及材料参数对模拟结果的影响。通过网格收敛性验证和与实验结果进行拟合，综合验证了计算模型中算法、边界条件和参数设定的可靠性。结果表明，在建模中若同时使用SPH算法和Lagrange算法，需要考虑粒子和网格大小对于模拟结果的影响。针对长杆弹撞击陶瓷靶的界面击溃模拟，不建议对陶瓷材料采用SPH粒子建模。相关建模和参数选择方法对后续陶瓷抗侵彻/界面击溃的数值模拟具有重要的指导意义。

A numerical simulation method for long rods penetrating into ceramic targets

Ceramics are widely used in armors because of high strength, low density and excellent ballistic performance. When long rods impact the ceramics, the long rods will flow radially along the ceramic surfaces without significant penetration. The special phenomenon is called interface defeat which has important practice application in the anti-penetration performance. For the long rods impacting the ceramic targets, a two-dimensional axisymmetric numerical model in which both the Lagrange method and smooth particle hydrodynamics (SPH) method are used, is established by using the software AUTODYN. The established model is applied to simulate the penetration of the long rod into the silicon carbide ceramic with a cover plate. By changing the impact velocity of the long rod, three different phenomena are obtained including interface defeat, dwell to penetration and direct penetration. Through the verification of mesh convergence and the comparison of the numerical results to the experimental results, the reliability of the algorithm, boundary conditions and parameter settings in the numerical model is comprehensively verified. The simulated results show that if the SPH and Lagrange methods are used at the same time, the influences of particle and mesh sizes need to be considered. It is not recommended to use the SPH method for simulating the interface defeat of the ceramic targets. The methods of the modeling and parameter selections are helpful for the subsequent simulations on ceramic anti-penetration and interface defeat.