船体时变可靠性分析

利用船体梁强度的单调退化特性，确定在设计寿命内船体强度的最小值。由船体强度的最小值和载荷的最大值，根据经典的时不变可靠性理论，构造了一种新的时变可靠性表述形式。同Guedes Soares和Garbatov的基于随机过程上跨率的时变可靠性表述形式相比，这种新的时变可靠性表述形式，既能够展现疲劳和腐蚀所导致的船体可靠性随时间的连续变化，同时又避免了数值积分的麻烦。因此这种方法计算量小，计算效率高。

Analysis of the Time Variant Reliability of Ship Hull

Using the property of the monotonic degradation of the ship hull strength with time, the minimum value of the ship hull strength in the design lifetime can be easily determined. Based on it, and with the maximum load in the design lifetime, a new time variant reliability formulation can be established by the classical time invariant reliability method. Compared to Guedes Soares and Garbatov's time variant reliability formulation, which is based on the up-crossing rate of a stochastic process, the new formulation not only exhibit the continuous decrease of the reliability of the ship hull with time but also avoid the tedious numerical integration. The new formulation is computationally efficient.