力学学报 ›› 2016, Vol. 48 ›› Issue (4): 944-952.doi: 10.6052/0459-1879-15-377

• 固体力学 • 上一篇    下一篇

一种新的多轴非比例低周疲劳寿命预测临界面模型

赵而年, 瞿伟廉   

  1. 武汉理工大学道路桥梁与结构工程湖北省重点实验室, 武汉 430070
  • 收稿日期:2015-10-14 修回日期:2016-04-20 出版日期:2016-07-15 发布日期:2016-07-28
  • 通讯作者: 赵而年,博士研究生,主要研究方向:钢结构的疲劳.E-mail:zhaoern@126.com E-mail:zhaoern@126.com
  • 基金资助:

    国家自然科学基金资助项目(51438002, 51378409).

A NEW PROPOSAL FOR MULTIAXIAL LOW-CYCLE FATIGUE LIFE PREDICTION UNDER NON-PROPORTIONAL LOADING

Zhao Ernian, Qu Weilian   

  1. Hubei Key Laboratory of Roadway Bridge & Structure Engineering, Wuhan University of Technology, Wuhan 430070, China
  • Received:2015-10-14 Revised:2016-04-20 Online:2016-07-15 Published:2016-07-28

摘要:

工程结构在服役过程中往往承受着复杂的多轴非比例循环荷载,在长期动力载荷作用下结构构件的失效主要为多轴非比例疲劳破坏. 文中基于圆管薄壁试件在拉-扭复合加载情况下的多轴疲劳试验结果,对比了广泛讨论的Kandil-Brown-Miller (KBM) 模型和Fatemi-Socie (FS) 模型对多轴非比例疲劳寿命的预测能力,分析了非比例加载条件引起多轴疲劳附加损伤的原因;针对FS 模型对不存在非比例附加强化的材料多轴疲劳寿命预测的不足,提出了一个能考虑非比例加载路径变化和材料附加强化效应双重作用的非比例影响因子,参照FS 准则提出了一种新的多轴非比例低周疲劳寿命预测临界面模型. 利用5 种材料的多轴非比例疲劳试验数据对该模型进行了试验验证,结果表明:采用文中提出的临界面模型预测的多轴非比例疲劳寿命与试验结果符合较好,预测精度优于FS 模型;同时,该模型对不存在非比例附加强化的材料的多轴疲劳寿命预测表现出更好的适用性,且能有效的提高不同类型材料的多轴非比例疲劳寿命预测精度.

关键词:

多轴疲劳|非比例路径|附加强化效应|临界面法|寿命预测

Abstract:

Engineering components are always in multiaxial and non-proportional stress states under complex service loading, and multiaxial fatigue is the primary failure mode during the long term vibration. In the present paper, the accuracy of multiaxial fatigue life estimation by the widely discussed Kandil-Brown-Miller (KBM) and FS model is investigated while the shortcoming of Fatemi-Socie (FS) parameter on fatigue life prediction of materials without additional cycle hardening is pointed out. Considering the dual influence of the additional cycle hardening and the rotation of principal stress/strain axes caused by non-proportional loading on multiaxial fatigue, which results in more fatigue damage, a new non-proportional influence factor is proposed, which is adopted for a modification to FS critical plane approach. Experimental results of five materials from tubular specimens under axial-torsional straining using sinusoidal wave forms in the literature are selected for the model verification. Comparing with FS parameter, the proposed critical plane damage parameter can significantly improve the accuracy of multiaxial fatigue lifetime prediction, especially for the materials without additional cycle hardening due to the non-proportionality of cycle loading.

Key words:

multiaxial fatigue|non-proportional loading|additional cycle hardening|critical plane approach|life prediction

中图分类号: 

  • TG111.8