钨铜变密度聚能射流侵彻模型及应用

钨铜是一种依靠机械摩擦结合的两相复合材料，在钨铜射流成型过程中，爆炸加载及拉伸程度的不同极易导致成分梯度及瞬时空隙，进而形成射流密度梯度。传统侵彻模型大多忽略材料中的微观结构变化，以射流密度定常为基本假设，对钨铜变密度射流侵彻深度的预测误差极大。综合考虑钨铜在聚能射流成型过程中材料拉伸及相分离导致的密度变化，引入射流密度与速度函数，对经典虚拟原点侵彻模型进行修正，建立了考虑射流可压缩性和成分梯度的钨铜变密度侵彻模型。以口径56 mm典型聚能结构为例，采用数值模拟及试验方法获得了钨质量百分比为75%的钨铜射流真实密度分布，并利用变密度侵彻模型计算了侵彻深度，同时利用X光脉冲摄影试验及静破甲试验对计算结果进行了验证。研究结果表明，钨铜变密度聚能射流侵彻模型比经典虚拟原点模型及局部密度修正模型计算的侵彻深度更加接近试验值，证实了钨铜变密度侵彻模型的正确性。

A Penetration Model for Tunsgsten-copper Shaped Charge Jet with Non-constant Density

Tungsten-copper (W-Cu) is a friction-bonded two-phase composite material with relative low interface bonding forces. A density deficit caused by phase separation and transient vacancy is often observed in W-Cu jet. Traditional penetration models are mainly based on the constant-density assumption neglecting the microstructural changes in shaped charge jet, which may trigger a considerable calculation error in the penetration prediction of W-Cu jet with non-cosntant density. A modified virtual origin penetration model for W-Cu jet is proposed by introducing the density and speed functions of jet, in which both material compressibility and composition gradient are considered. Based on a typical shaped charge structure, the true density distribution of 75wt%W-Cu jet was obtained, and the calculated penetration depth was validated by the experiment. The results show that the W-Cu penetration model can greatly improve the calculation accuracy compared with the traditional virtual origin model and partially modified model.