上海交通大学学报(自然版) ›› 2015, Vol. 49 ›› Issue (02): 214-219.

• 交通运输 • 上一篇    下一篇

基于改进裂纹扩展模型的船舶焊接结构疲劳寿命可靠性预报

闫小顺,黄小平   

  1. (上海交通大学 海洋工程国家重点实验室,上海 200240)
  • 收稿日期:2014-03-07 出版日期:2015-02-28 发布日期:2015-02-28
  • 基金资助:

    国家自然基金资助项目 (51279102)

Prediction of Fatigue Life Reliability for Ship Details Based on Crack Growth

YAN Xiaoshun,HUANG Xiaoping   

  1. (State Key Laboratory of Ocean Engineering, Shanghai Jiaotong University, Shanghai 200240, China)
  • Received:2014-03-07 Online:2015-02-28 Published:2015-02-28

摘要:

摘要:  结合考虑应力比的改进Paris公式,推导焊接结构疲劳极限状态方程.采用数值积分方法求解疲劳裂纹扩展寿命,结合Monte Carlo模拟方法给出了船舶结构疲劳寿命可靠性预报的流程,并对某大型集装箱船甲板进行了疲劳寿命可靠性预报,讨论了各参数对预报结果的影响.结果显示,采用数值积分方法的计算结果与cycle-by-cycle方法的计算结果差别较小,而计算速度相比于cycle-by-cycle方法有显著提高.此外,改进Paris公式的应用可以减小预报结果的变异系数,初始裂纹尺寸对疲劳寿命及可靠性影响显著,最终裂纹尺寸则影响不大.文中所述数值积分方法和可靠性预报流程可为工程结构快速进行疲劳裂纹扩展寿命计算或疲劳寿命可靠性预报提供参考.

关键词: 船舶焊接结构, 可靠性, 疲劳寿命, 裂纹扩展, 应力比

Abstract:

Abstract: In this paper, a limit state equation was derived by using an improved model of Paris law. A more efficient numerical integration method was described and the verification showed that the result of this method was in good agreement with that of the cyclebycycle method. A flowchart for prediction of fatigue life reliability of ship details by using Monte Carlo simulation was given. Based on this procedure, a demonstration was done for predicting the fatigue life reliability of a detail on deck of a container ship. In addition, the influences of variables on prediction result were discussed. It is shown that the improved Paris model can reduce the variation of predicted fatigue life. Initial crack size affects the results a lot while the critical crack size does not. The method proposed can provide reference for fast prediction of fatigue life or obtaining reliability of other engineering structures.

Key words: ship welded structure reliability, fatigue, crack propagation, stress ratio

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