分子动力学方法在金属材料动态响应研究中的应用

Application of Molecular Dynamics Simulation to Dynamic Response of Metals

随着计算机技术和实验诊断技术的发展,分子动力学(MD)方法在冲击动力学领域发挥着越来越重要的作用。从 MD 方法的基本原理出发,介绍了积分算法、相互作用势、常用的数据处理方法,系统梳理了 MD方法在冲击加载下金属材料的塑性变形、相变、动态损伤断裂(层裂)等研究的应用。其中:在冲击塑性方面,主要阐述单晶、双晶和多晶体系中的塑性变形机理,以及变形过程与微结构等的联系;在冲击相变方面,主要以金属铁为例,介绍耦合冲击相变与冲击塑性的 MD计算模拟工作;在动态损伤断裂方面,主要阐述冲击加载下金属材料中孔洞动态演化及贯通、激光加载下材料的动态响应等工作。最后,对 MD方法的未来应用进行了展望,以期为相关领域的研究提供参考。

With the development of computer science and technology and diagnostic techniques, molecular dynamics (MD) simulation plays an increasingly important role in the field of shock dynamics. This review presents the basic principle of MD firstly, followed by integrated algorithm, inter-atom potentials, and some widely used data processing methods. Then the applications of MD in the plastic deformation of metals, phase transitions, and damage and fracture under shock loading (spallation) are presented in a systematic manner. The shock plasticity is focused on the micro-mechanisms of plastic deformation and the relationship between the deformation process and micro-structures in single crystals, twin crystals, and polycrystals. In terms of shock-induced phase transitions, the iron is taken as an example to emphasize the research focusing on the coupling of shock transitions and shock plasticity. The contents of dynamic damage and fracture mainly cover the void evolution and coalescence, dynamic response of materials under laser loading, and so on. Finally, a brief summary and perspective of MD regarding to future applications are offered, intending to provide the further information for the related researchers.