金属柱壳碎裂行为及载荷、结构、缺陷影响的研究

金属柱壳碎裂过程是一个受材料、载荷、结构、缺陷等多种因素影响的复杂物理现象，存在包括拉伸、剪切、绝热剪切及其混合型等多种断裂模式。本项目拟设计实验对载荷、结构、几何缺陷等因素对柱壳膨胀碎裂过程的影响开展研究，通过对碎片断口及金相分析辨识断裂模式，探讨不同爆炸载荷作用下柱壳的断裂模式及变化规律，以及加载率对柱壳碎片尺寸分布及特征尺寸的影响。区分不同断裂模式下的材料碎裂特性的异同。在此基础上，进一步就柱壳几何缺陷对碎裂过程、碎片特征尺寸的影响开展实验研究，揭示表面周期性几何缺陷特征对金属柱壳碎片尺寸影响及控制规律。

Explosively driven fragmentation of ductile metals cylinders is a highly complex phenomenon in which several mechanisms lead to fracture can be identified, affected by many factors such as the characteristics of the impulsive loadings, the materials, the geometry of the shell structures, etc. In this study, tubular metal specimens will explosively expanded to fragmentation, and the effects of explosive energy, configuration, geometric imperfections, shall be investigated on the deformation and fracture behavior of the cylinders experimentally. Fractographic and metallographic examination are carried out on the analysis of the fragmentations，to identify the mode of fracture. The rule of the fracture mode variation with explosion loading will be discussed. The effect of strain rate on the fragments distribution and its characteristic size will be studied experimentally, in which the differences and similarities of the fragmentation behavior for materials in different fracture modes concern. Furthermore, the fracture initiation, fracture mechanism, and characteristic size of the fragments affected by geometric imperfections of cylinder is studied experimentally. The rule of the fragments self-organization space affect by periodicity of defect will be acquainted.