铜在强冲击载荷下的细观力学行为数值模拟  

Numerical Simulation of Microscopic Dynamic Behavior in the Copper under Explosively Dynamic Loading

作　　者：杨瑞[1] 王金相[1] 周楠[1] 彭楚才[1] 谢君[1] 

机构地区：[1]南京理工大学瞬态物理重点实验室,江苏南京210094

出　　处：《高压物理学报》2013年第3期461-467,共7页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(10902054;11272158);中国博士后基金(2011M500929);江苏省博士后基金(1101003B);部委技术基础项目(C1820130005)

摘　　要：利用Voronoi方法建立了多晶铜的细观几何模型,能够反映晶粒几何形状和晶界的不规则性,基于晶界固连-失效模型反映晶界结合特征,借助LS-DYNA非线性有限元程序,从细观角度对爆炸冲击载荷作用下铜的晶粒变形、热沉积行为进行了数值模拟。配合高压熔点理论和晶粒生长理论,从热力学角度分析了晶粒细化的可行性,结合实验结果对晶粒细化进行了定性验证。研究结果表明,通过构建的数值模拟方法,对多晶铜冲击压缩下的晶粒与晶界的变形机制、热沉积进行研究是可行的;晶界处易于形成应力集中现象,塑性变形和由此引起的温升大于晶粒内部;由宏观绝热压缩和由细观畸变引起的整体温升不会引起晶粒的长大。Voronoi method was adopted to establish the micro-geometry model of polycrystalline copper which can reflect the irregularities of grain geometric shape and grain boundaries. The Tie-Break model was used to reflect the binding characteristics of grain boundary. Then the grains deformation and thermal deposition behavior under explosive dynamic loading were studied from the microscopic view recur to LS-DYNA nonlinear finite element program. Finally, the possibility of grain refining was anslyzed by high pressure melting point theory and grain growth theory,and the analysis was proved qualitatively by experimental results. The results show that it is feasible to research grain and grain boundary deformation mechanisms as well as the heat deposition for the shock compressed polycrystalline copper by the numerical simulation method built in this work. Stress concentration is easy to form on the grain boundaries, plastic deformation and temperature rise on the grain boundaries are greater than those of the grain interior. The temperature rise caused by the macro-adiabatic compression and the micro-plastic deformation does not cause grain growth.

关 键 词：冲击动力学 晶粒细化 热力学行为 Voronio 

分 类 号：O347.3[理学—固体力学]