东北大学学报(自然科学版) ›› 2007, Vol. 28 ›› Issue (12): 1741-1744.DOI: -

• 论著 • 上一篇    下一篇

热疲劳裂纹开裂过程的有限元模拟

闫明;孙志礼;杨强;陈凤熹;   

  1. 东北大学机械工程与自动化学院;东北大学机械工程与自动化学院;东北大学机械工程与自动化学院;中国兵器系统总体部 辽宁沈阳110004;辽宁沈阳110004;辽宁沈阳110004;北京100089
  • 收稿日期:2013-06-24 修回日期:2013-06-24 出版日期:2007-12-15 发布日期:2013-06-24
  • 通讯作者: Yan, M.
  • 作者简介:-
  • 基金资助:
    总装备部预研项目(9140A19020206BQ0601)

FEM simulation of initial cracking process due to thermal fatigue

Yan, Ming (1); Sun, Zhi-Li (1); Yang, Qiang (1); Chen, Feng-Xi (2)   

  1. (1) School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004, China; (2) China North Group Corporation, Beijing 100089, China
  • Received:2013-06-24 Revised:2013-06-24 Online:2007-12-15 Published:2013-06-24
  • Contact: Yan, M.
  • About author:-
  • Supported by:
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摘要: 用有限元方法并考虑材料的多线性随动强化性质对带有裂纹的简单试件模型进行热疲劳分析,研究热疲劳裂纹张开的过程和规律。在升温半循环中材料受热膨胀,热疲劳裂纹保持闭合,两裂纹面相互挤压,当压缩应力达到材料的屈服极限,产生压缩塑性变形;在降温半循环中试件有恢复原有形状的趋势,但由于升温半循环中生成的压缩塑性变形不可恢复,裂纹逐渐张开.热疲劳裂纹张开的一个必要条件是高温侧材料在升温过程产生压缩塑性变形,这与普通疲劳裂纹不同.

关键词: 热疲劳, 开裂过程, 多线性随动强化, 有限元方法

Abstract: The process and rules of the initial cracking due to thermal fatigue are studied considering the multi-linear kinematic hardening of material, with a simple sample as model analyzed by FEM. During the half cycle of warming the crack is closing and its two wall surfaces extrude each other because of thermal expansion. Then, the plastic compressive deformation comes into being when the compressive stress reaches the yield limit. During the half cycle of cooling, the sample tends to restore its original shape. However, because the plastic compressive deformation formed before cannot come back, the crack opens gradually. One of the necessary conditions of the initial cracking due to thermal fatigue is that the material on high temperature side has been deformed compressively and plastically, which is different from the cracking due to common fatigue.

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