开发一种可靠的数值预测技术来模拟陶瓷装甲在高速冲击(HVI)下的弹道响应,以节省测试成本并缩短设计周期至关重要。在目前的手稿中,采用FE转换SPH技术,系统地模拟了钨重合金(WHA)碎片对99.5%氧化铝(AD995)装甲的渗透的一系列实验。将数值结果与实验结果进行比较,发现FE转换-SPH方法在预测穿透深度方面相当有效,剩余速度,碎片的长度和质量,再现陶瓷的裂纹形式。数值模型在算法方面的适用性和准确性,验证材料模型参数和接触定义。然后,结合校准数值模型的相关参数,探讨覆盖层厚度对装甲性能的影响。已经确定了一些关于盖板的机制来作用于装甲性能,如裂缝锥半角的改变,陶瓷吸收的能量比例,碎片如雨后春笋般变形,等。多机构叠加的结果是,1毫米覆盖层装甲具有最佳的弹道性能,这表明与4.96g/cm2面积密度的双层装甲相比有24.6%的改进,仅以面积密度增加15.7%为代价,当背板厚度保持为2mm时;对于4.96g/cm2的恒定面密度,1mm的覆盖层也有望是最佳选择,装甲性能提高10.7%。
It is of extreme importance to develop a reliable numerical prediction technique to simulate the ballistic response of ceramic armor subjected to high-velocity impact (HVI) to economize the test cost and shorten the design period. In the present manuscript, a series of experiments on tungsten heavy alloy (WHA)
fragment\'s penetration into 99.5% alumina (AD995) armors are systematically simulated by employing the FE-converting-SPH technique. The numerical results are compared with the experimental counterparts to find that the FE-converting-SPH method is fairly efficient in predicting the depth of penetration, the residual velocity, length and mass of
fragment, and reproducing the crack forms of ceramic. The applicability and accuracy of the numerical model in terms of the algorithm, material model parameters and contact definitions are validated. Then, the relevant parameters of the calibrated numerical model are incorporated to explore the influence of cover-layer thickness on the armor performance. A few mechanisms regarding the cover plate have been identified to act on the armor performance, such as the alteration of fracture cone half-angle, proportion of energy absorbed by ceramic, mushrooming deformation of
fragment, etc. The result of multi-mechanism superposition is that the best ballistic performance is endued with 1 mm cover-layer armor, which demonstrates a 24.6% improvement over the bi-layer armor with 4.96 g/cm2 area density, only at the cost of 15.7% increase in areal density, when back-plate thickness is held as 2 mm; for a constant area density of 4.96 g/cm2, a 1 mm cover-layer is also expected to be the best choice, with 10.7% improvement in armor performance.