摘要
船舶服役期间工程技术人员需要对已检测到裂纹的构件进行剩余疲劳寿命可靠性评估,以便做出维修决策。鉴于基于S-N曲线和累计损伤理论的常规疲劳寿命预报方法对于损伤难以明确定义,本文基于裂纹扩展理论对船舶疲劳热点剩余疲劳寿命可靠性预报方法进行研究。在考虑应力比和应力强度因子幅门槛值的情况下,研究求解裂纹扩展预报的快速数值计算方法。通过与蒙特卡洛模拟相结合,预报可靠性指标随时间的变化曲线、一定存活率下的剩余疲劳寿命等。以油船上某疲劳热点为研究对象,进行剩余疲劳寿命可靠性预报,为工程应用提供参考。
It is necessary for engineers to evaluate the reliability of residual fatigue life for ship details with initial crack during ship service. It is difficult to define the existing damage clearly when the Cumulative Fatigue Damage（ CFD） theory based assessment was used. The method of reliability prediction of residual fatigue life for cracked ship details based on fatigue crack growth（ FCP） has been discussed in this paper. Numerical calculation method for fatigue crack growth prediction based on the unique crack growth rate curve model,in which the stress ratio and threshold of stress intensity factor（ SIF） were taken into consideration,was investigated. By combining with Monte Carlo Simulation（ MCS）,the reliability index versus time and the fatigue life with a certain probability of survival have been derived. Finally,an example of reliability prediction of residual fatigue life for a welded joint with initial crack in a tanker was given. The presented method can provide a reference for engineering practice.
出处
《舰船科学技术》
北大核心
2016年第2期27-31,共5页
Ship Science and Technology
