多次冲击加载下微层裂的压缩回帖及破碎过程研究

As an extremely complex phenomenon in the basic study and engineering application of weapon physics, dynamic compression and damage process of melted metal subjected to multiple shock loading is of focused subject in the weapon laboratories. However, lacking the physical model, experimental measurements and numerical computations, it remains very poor to understanding the recollection and fragmentation of micro-spall in experiments and numerical simulations. .In this program, based on the previously conducted microspall examination of the Sn sample, by designing the explosively multiple-shock experimental setup and combing the multiple diagnostics, dynamic information of the recompressed micro-spall is obtained to elucidate the evolution process of recollection and fragmentation. Varying the loading conditions of the metal samples, recompression and breakup behaviors and differences are comparatively analyzed. By constructing the physical model of recollection and fragmentation to embed into the numerical software, numerical simulation studies the multiple-shock event of the metal material, verifying with the experimental data, to deepening its physical knowledge. The results contribute to the experimental diagnostic and physical modeling of the multiple-shock process in the early state of the implosive weapon.

作为武器基础研究及其工程应用中一个极其复杂动力学现象，多次冲击加卸载下熔化金属的压缩及动态损伤问题是当前国内外武器实验室关注的焦点。但由于物理模型、诊断技术及数值计算能力的欠缺，导致目前在实验研究或数值模拟对首次形成的微层裂被后继的多次冲击压缩回帖和破碎物理过程认识存在严重不足。.本项目基于前期开展的单次冲击加载下低熔点金属Sn微层裂现象研究，利用设计的爆轰主导多次冲击加载实验装置，联合多种适用性诊断技术，重点获取再次冲击加载微层裂物质的动力学特征数据，深入认识微层裂再压缩回帖及破碎的动态演化过程，对比分析不同加载条件下微层裂的再压缩和破碎行为及差异；构建微层裂再压缩及破碎的物理模型，数值模拟研究多次加载熔化金属的压缩及动态碎裂过程，与实验结果校验迭代，深化该动力学过程的物理认识。研究成果将为武器内爆早期动力学阶段呈现的多次冲击加卸载物理过程的实验诊断和物理建模提供重要支撑。

本项目针对多次冲击加载下层碎裂物质回贴及破碎过程的动态行为开展了实验和数值模拟研究。基于一维平面爆轰的二次加载实验装置并选择低熔点金属Sn为研究对象，开展了多种加载状态下层碎裂物质回贴及破碎行为的实验研究，利用可见光照相、X光照相、多谱勒测速及Asay膜、Asay窗技术获取了Sn样品的加载状态、表面喷射及层碎裂物质密实状态的定量数据，深化了该过程的物理认识。同时，发展了层碎裂物质再压缩过程的物理模型并基于模拟层碎裂物质不同密实状态的Sn粉冲击压缩实验进行了校验标定，结合宏/微观数值模拟分析了层碎裂物质的再压缩行为，初步阐明了其压缩行为及演化机制。