船体在疲劳和腐蚀损伤下的可靠性

在疲劳和腐蚀作用下，船体梁舯剖面模数折减，导致极限承载能力下降，在此基础上进行可靠性分析。文中腐蚀率是一个有常数平均值的随机变量，疲劳裂纹根据Paris公式计算，当静水弯矩和波浪弯矩的组合值超过船体梁极限承载能力时，发生船体梁失效。以一艘散货船为例，计算其可靠性随时间的变化。计算结果可为船东和船级社评估船舶营运期间疲劳和腐蚀对船舶可靠性的影响提供参考。

Reliability of Ship Hull Subjected to Fatigue and Corrosion

In this paper,a reliability analysis based on the ultimate strength of the midsection of ship hull girders subjected to degradation due to corrosion and fatigue is presented.Corrosion is considered as a random process with a constant mean value and crack propagation is predicted according to the Paris equation.Fatigue occurs when the combined value of still-water and wave-induced bending moments exceeds the ultimate strength of hull girders.Time-varying reliability of the hull girder of a bulk carrier is quantified.The calculation results can be used by ship owners and classification societies for reference in their assessing reliability margins related to corrosion and fatigue of a ship in its lifecycle.