Numerical Simulation of Microscopic Dynamic Behavior in the Copper under Explosively Dynamic Loading
-
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。Abstract: 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 analyzed 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.
-
Key words:
- impact dynamics /
- grain refining /
- thermo-dynamic behavior /
- Voronoi
-
Li J, Weng G J. A secant-viscosity composite model for the strain-rate sensitivity of nanocrystalline materials [J]. Int J Plastic, 2007, 23(12): 2115-2133. Xiao G H, Tao N R, Lu K. Effects of strain, strain rate and temperature on deformation twinning in a Cu-Zn alloy [J]. Scripta Mater, 2008, 59(9): 975-978. Wang H T, Yang W. Mechanical behavior of nanocrystalline metals [J]. Advances in Mechanics, 2004, 34(3): 314-326. (in Chinese) 王宏涛, 杨卫. 纳米晶金属的力学行为 [J]. 力学进展, 2004, 34(3): 314-326. Benkasse S, Capolungo L. Mechanical properties and multi-scale modeling of nanocrystalline materials [J]. Acta Mater, 2007(55): 3563-3572. Wang Y M, Wang K, Pan D, et al. Microsample tensile testing of nanocrystallinne cooper [J]. Scripta Mater, 2003, 48(12): 1581-1586. Zhang L D. Nanomaterials and nanotechnology in China: Current status of applicationand opportunities for commercialization [J]. Materials Review, 2001, 15(7): 2-5. (in Chinese) 张立德. 我国纳米材料技术应用的现状和产业化的机遇 [J]. 材料导报, 2001, 15(7): 2-5. Cai B, Kong Q P, Lu L, et al. Low temperature creep of nanocrystalline pure copper [J]. Mater Sci Eng A, 2000, 286(1): 188-192. Guduru R K, Murty K L, Youssef K M, et al. Mechanical behavior of nanocrystalline copper [J]. Mater Sci Eng A, 2007, 463(1-2): 14-21. Zheng C, Zhang Y W. Atomistic simulations of mechanical deformation of high-angle and low-angle nanocrystalline copper at room temperature [J]. Mater Sci Eng A, 2007, 423(1-2): 97-101. Wang J X, Zhou N, Li B M, et al. Fabrication of nanocrystalline copper by explosive loading and its dynamic mechanics properties [J]. Combustion, Explosion and Shock Waves, 2011, 47(3): 369-373. Wang J X, Zhou N. Study on the grain size distribution rule and influence factors of nanocrystalline copper fabricated under explosive loading [J]. Chinese Journal of High Pressure Physics, 2011, 25(6): 501-507. (in Chinese) 王金相, 周楠. 爆炸载荷下纳米晶铜晶粒度分布及影响因素研究 [J]. 高压物理学报, 2011, 25(6): 501-507. Kang J X, Wang Z H, Zhao L M. Studay on the quasi-static mechanical proerties of cellular metal using voronoi tessellation [J]. Engineering Mechanics, 2011, 28(7): 203-209. (in Chinese) 康锦霞, 王志华, 赵隆茂. 采用Voronoi模型研究多孔金属材料准静态力学特性 [J]. 工程力学, 2011, 28(7): 203-209. Zhang Q M, Liu Y, Huang F L. Dynamic Behavior of Materials [M]. Beijing: National Defense Industry Press, 2006: 165-170. (in Chinese) 张庆明, 刘彦, 黄风雷. 材料的动力学行为 [M]. 北京: 国防工业出版社, 2006: 165-170. Wang H T, Yang W, Ngan A H W. Enhanced diffusivity by triple junction networks [J]. Scripta Mater, 2004, 52(1): 69-73. Johnson G R, Cook W H. Fracture characteristics of three metals subjected to various strains, strain rates, temperatures and pressures [J]. Eng Fract Mech, 1985, 21(1): 31-48. Tang W H, Zhang R Q. Introduction to Theory and Computation of Equations of State [M]. 2nd ed. Beijing: Higher Education Press, 2008: 134-136. (in Chinese) 汤文辉, 张若棋. 物态方程理论及计算概论 [M]. 第2版. 北京: 高等教育出版社, 2008: 134-136. Andrievski R A. Review stability of nanostructured materials [J]. J Mater Sci, 2003, 38(7): 1367-1375. Murty B S, Datta M K, Pabi S K. Structure and thermal stability of nanocrystalline materials [J]. Sadhana, 2003, 28(1-2): 23-45.
点击查看大图
计量
- 文章访问数: 6670
- HTML全文浏览量: 320
- PDF下载量: 336