船体在腐蚀损伤下随时间变化的可靠性分析
谭可盈1, 2 , 金永兴1
(1. 上海海事大学商船学院,上海 200135; 2. 缅甸海事大学造船系,缅甸仰光)
摘 要:分析一种船体腐蚀影响下随时间变化的船体结构可靠性计算方法. 通过可靠性函数对船舶于规定运用期限内的不同时段的状况进行计算,并以一艘散货船为例,与传统的方法进行计算和比较,得出较为实时精确的结论.
关键词: 可靠性; 腐蚀; 剖面模数; 总弯矩; 船体抗极限能力
Analysis on time variant reliability of primary ship hull subjected to corrosion
Thandar Knaing, J IN Yongxing1
(1. MarchantMarine College, ShanghaiMaritime Univ. , Shanghai 200135, China;
2. NavalArchitecture Department, MyanmarMaritime Univ. , Yangon, Myanmar)
Abstract: A methodology to assess the time2variant reliability of the p rimary ship structure with hull girder degradation of corrosion is analyzed. The reliability function is calculated at discrete points during the ship ’s life. A samp le calculation is performed for the reliability of a bulk carrier comparingwith the p resent p ractice and traditional one. And it is shown that, whenever degradation is p resent, the time dependent reliability calculated with the p resent p ractice showsmore accurate dynamic result towards the end of the ship’s life.
Key words: reliability; corrosion; section modulus; bending moment; hull resisting capacity
CLC number: O34 Documen t code: A
0 Introduction
In the recent years, many reliability app roaches have been app lied to the assessment of p robability of failure of the p rimary ship hull structure. Before 1970’s, commonly used definiting method and struc2
tural reliability is evaluated over the lifetime of the structure. Formulation of reliability of ship hulls for such a long time frame is not taken into account on the different mechanisms of degradation of the structural resistance. And the app roaches are one load and one strength variable, in which the variables are describe dby their p robability distributions, and the measure of safety is p rovided by the p robability of failure.
Some app roaches are described by the mean value and standard deviation of load and resistance, and safety of the structure is quantified by the reliability index with app lications of First Order Second Moment ( FOSM )methods.
