计算物理 ›› 2014, Vol. 31 ›› Issue (4): 471-478.

• 研究论文 • 上一篇    下一篇

韧性材料的微裂纹扩展与分叉的晶体相场模拟

高英俊1,2, 罗志荣1,2, 邓芊芊1, 黄礼琳1, 林葵1   

  1. 1. 广西大学广西有色金属及特色材料加工重点实验室, 南宁 530004;
    2. 广西大学物理科学与工程技术学院, 南宁 530004
  • 收稿日期:2013-08-21 修回日期:2013-11-25 出版日期:2014-07-25 发布日期:2014-07-25
  • 作者简介:高英俊(1962-),男,博士,教授,博士生导师,主要从事材料微结构设计与计算模拟实验研究,E-mail:gaoyj@gxu.edu.cn
  • 基金资助:
    国家自然科学基金(51161003);广西自然科学基金重点项目(2012GXNSFDA053001);广西大学广西有色金属及特色材料加工重点实验室开放基金(GXKFJ12-01);广西大学科研基金(XJZ110611)资助项目

Phase-Field-Crystal Modeling of Microcrack Propagation and Branching in Ductile Materials

GAO Yingjun1,2, LUO Zhirong1,2, DENG Qianqian1, HUANG Lilin1, LIN Kui1   

  1. 1. Guangxi Key Laboratory for Non-ferrous Metal and Featured Materials, Guangxi University, Nanning 530004, China;
    2. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China
  • Received:2013-08-21 Revised:2013-11-25 Online:2014-07-25 Published:2014-07-25

摘要: 采用晶体相场方法研究韧性单晶材料在双轴拉伸条件下微裂纹扩展与分叉的演化过程,分析应变、温度、初始裂口形状等因素对裂纹扩展和分叉的影响.结果表明:对于简单的单向拉伸,应变需要达到一定的临界值,裂纹扩展才会启动.对于二组相互垂直的双轴拉伸作用,当应变达到临界值后,裂纹扩展过程中会发生分叉现象.温度越高,裂纹扩展越快且分叉越多.裂纹在扩展过程中,体系能量不断降低,当裂纹出现分叉时,体系能量降低得更快.在裂纹扩展过程中,有时是会在裂尖处前方出现微小的空洞,类似在裂纹尖端前方出现位错发射情况,这些微小的空洞逐渐扩大连成裂纹.本文所得结果与相关模拟结果和实验结果符合.

关键词: 晶体相场方法, 微裂纹扩展, 应变, 韧性材料

Abstract: Morphology of microcrack propagation and crack branching of single crystal ductile materials under tensile are simulated with phase-field-crystal method. It shows that shape of notch has a strong effect on crack propagation. With uniaxial tension crack propagation appears if only strain reaches a critical value. With biaxial tension a crack branches if only strain reaches a critical value. Temperature parameter takes significant effects on crack propagation. The smaller the temperature parameter is (the temperature is higher), the faster the cracks propagate and the more the crack branches are. It is observed that free energy of system decreases with time and decreases faster after crack starts to branch. During crack propagation, disconnectedly isolated cavities around the main cracks can be found and these defects become new cracks. They grow up along a line and become a branching crack. Simulated results are in agreement with other simulations and experimental results.

Key words: phase-field-crystal method, microcrack propagation, strain, ductile materials

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