金属热处理 ›› 2020, Vol. 45 ›› Issue (5): 210-214.DOI: 10.13251/j.issn.0254-6051.2020.05.041

• 数值模拟 • 上一篇    下一篇

淬火残余应力对铝合金厚板裂纹应力强度因子及扩展趋势的影响

罗家元, 贾二锁   

  1. 重庆交通大学 机电与车辆工程学院 山区桥梁结构与材料教育部工程研究中心, 重庆 400074
  • 收稿日期:2019-11-18 出版日期:2020-05-25 发布日期:2020-09-02
  • 作者简介:罗家元(1978—),男,副教授,博士,主要研究方向为残余应力评估及消除、结构疲劳寿命等,E-mail:jiayuan_luo@126.com
  • 基金资助:
    重庆市教委科学技术研究项目(KJ1705129,KJQN201801610);重庆市博士后特别资助项目(Xm2017034);重庆交通大学山区桥梁结构与材料教育部工程研究中心开放式基金(QLGCZX-JJ2015-2);重庆第二师范学院校级科研项目(KY201701A)

Effect of quenching residual stress on stress intensity factors and propagation trend of crack of aluminum alloy thick plate

Luo Jiayuan, Jia Ersuo   

  1. Mountain Bridge Structure and Materials Ministry of Education Engineering Research Center, School of Mechatronics and Vehicle Engineering, Chongqing Jiaotong University, Chongqing 400074, China
  • Received:2019-11-18 Online:2020-05-25 Published:2020-09-02

摘要: 为探究淬火残余应力对铝合金厚板疲劳裂纹扩展的影响规律,建立7075铝合金厚板表面三维裂纹数值仿真模型。采用顺序热力耦合法求解淬火残余应力场,将残余应力场作为初始载荷条件求解裂纹应力强度因子,并与无残余应力场的应力强度因子值进行对比,研究两种条件下应力强度因子的分布规律和两者之间的异同;通过分析在初始淬火残余应力条件下不同半径裂纹受不同均匀拉应力荷载作用时的裂纹应力强度因子随裂纹位置角的演变曲线,探究淬火残余应力对裂纹扩展趋势的影响规律。结果表明,淬火残余应力的存在改变了铝合金厚板应力强度因子的分布规律和裂纹的扩展趋势,淬火残余应力使表层附近的裂纹扩展受到遏止,裂纹易于在厚度方向优先扩展。

关键词: 淬火残余应力, 铝合金, 应力强度因子, 裂纹扩展

Abstract: In order to explore the influence law of quenching residual stress on the fatigue crack propagation of the aluminum alloy thick plate, a numerical simulation model of three-dimensional crack on 7075 aluminum alloy plate was developed. The method of sequentially coupled thermal-stress was used to solve the quenching residual stress field, and the residual stress field was taken as the initial load condition to solve the stress intensity factors of the crack, then compared it with the value of stress intensity factors without residual stress field. Under these two conditions, the distribution of stress intensity factors and their similarities and differences were studied. By analyzing the evolution curve of crack stress intensity factors along with the crack position angle under different uniform tensile stress loading in different crack radius with initial quenching residual stress, the influence law of the quenching residual stress on crack propagation trend was found out. The results show that the existence of quenching residual stress changes the distribution of stress intensity factors and crack propagation trend of the aluminum alloy thick plate, and the crack propagation near the surface is restrained by quenching residual stress.The crack tends to propagate preferentially in the thickness direction.

Key words: quenching residual stress, aluminum alloy, stress intensity factors, crack propagation

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