爆轰加载下金属锡层裂破碎数值模拟

摘要

Spallation and fragmentation of tin, a low-melting point metal under explosive loading were numerically simulated. The numerical method and material model used were validated by the experimental results. Thereby, the temporal evolution and spatial distribution of the physical quantities in the Sn specimens were compared to explore the interaction between the stress waves and the material in the specimen under impact loading and unloading. Furthermore, the dynamic behaviors of the specimens with various thicknesses under explosive loading were in-depth analyzed to further understand the evolution mechanism of the spallation and fragmentation under the combination action of the reflective rarefaction wave from the free surface, the lateral rarefaction wave and the incident rarefaction wave. The results show that for the thin specimen, the early spallation and fragmentation are dominated by the reflective rarefaction wave. With increasing the thickness of the specimen, the region dominated by the reflective rarefaction wave becomes smaller, and meanwhile the region dominated by the incident rarefaction wave and the lateral rarefaction wave becomes larger.%对爆轰加载下低熔点金属锡的层裂破碎问题开展了数值模拟。在利用实验数据对所采用数值方法和材料模型开展对比验证的基础上，通过对样品内部物理量时间及空间分布演化对比分析，剖析了冲击加-卸载中样品内部应力波与材料相互作用过程。此外，通过对比分析不同厚度锡样品在爆轰加载下的动态行为特征，进一步认识了自由面反射稀疏波、边侧稀疏波和入射稀疏波共同作用下层裂破碎演化机制。结果表明，当样品较薄时，层裂破碎行为由反射稀疏波主导；随着样品厚度的增大，反射稀疏波主导区缩小，入射稀疏波和边侧稀疏波主导区逐渐增大。