华南理工大学学报(自然科学版) ›› 2014, Vol. 42 ›› Issue (4): 118-123,130.doi: 10.3969/j.issn.1000-565X.2014.04.018

• 机械工程 • 上一篇    下一篇

基于等效初始缺陷尺寸和功率谱法的起重机疲劳寿命预测

陆念力 詹伟刚   

  1. 哈尔滨工业大学 机电工程学院,黑龙江 哈尔滨 150001
  • 收稿日期:2013-12-17 修回日期:2014-01-14 出版日期:2014-04-25 发布日期:2014-03-03
  • 通信作者: 詹伟刚(1985-),男,博士生,主要从事工程机械结构强度和疲劳研究. E-mail:zhanweigang@163.com
  • 作者简介:陆念力(1955-),男,教授,博士生导师,主要从事工程机械结构刚度、强度、稳定性、可靠性分析和故障诊断研究.E-mail:n.lu@hit.edu.cn
  • 基金资助:

    国家 “十二五” 科技支撑计划项目(2011BAJ02B01)

Fatigue Life Prediction of Crane Based on Equivalent Initial Flaw Size and Power Spectral Density

Lu Nian- li Zhan Wei- gang   

  1. School of Mechatronics Engineering,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China
  • Received:2013-12-17 Revised:2014-01-14 Online:2014-04-25 Published:2014-03-03
  • Contact: 詹伟刚(1985-),男,博士生,主要从事工程机械结构强度和疲劳研究. E-mail:zhanweigang@163.com
  • About author:陆念力(1955-),男,教授,博士生导师,主要从事工程机械结构刚度、强度、稳定性、可靠性分析和故障诊断研究.E-mail:n.lu@hit.edu.cn
  • Supported by:

    国家 “十二五” 科技支撑计划项目(2011BAJ02B01)

摘要: 基于 Kitagawa- Takahashi 图提出了一种计算起重机金属结构等效初始裂纹尺寸及其统计学分布的方法,此方法的优点在于只用到疲劳寿命极限和疲劳裂纹扩展门槛值,与随机变化的载荷应力无关.为计及载荷次序以及裂纹闭合效应对疲劳寿命的影响,基于载荷的功率谱密度,给出了一种频域分析的起重机疲劳寿命预测方法.为验证所提方法的有效性,将文中方法的预测结果与文献中的起重机箱形梁的疲劳实验结果进行对比,结果表明估算寿命与实验寿命吻合,文中方法具有实用性和可靠性.

关键词: 起重机, 疲劳寿命预测, 初始裂纹尺寸, 功率谱密度, 裂纹扩展

Abstract:

Proposed in this paper is a method to calculate the equivalent initial flaw size (EIFS) and its statisticaldistribution for crane's metal structure.The method,which is based on the Kitagawa- Takahashi diagram,uses fatiguelimit and fatigue crack growth threshold to calculate the EIFS,without the participation of randomly applied loads.Moreover,considering the effects of load sequence and crack closure on the predicted fatigue life,a frequency- do-main analysis method for crane fatigue life prediction is proposed based on the power spectral density of the load.Thefatigue life of crane box girder predicted by the proposed method is compared with the test ones presented in litera-tures,and a good consistency is revealed,which means that the proposed prediction method is applicable and reliable.

Key words: crane, fatigue life prediction, initial crack length, power spectral density, crack growth

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