随机海浪中船舶非线性横摇的首次穿越概率(英文)  

First Passage Probability of Nonlinear Ship Rolling in Random Seas

作　　者：王迎光[1] 黄志龙[2] 谭家华[1] 

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200030 [2]浙江大学应用力学研究所,杭州310027

出　　处：《船舶力学》2008年第6期870-879,共10页Journal of Ship Mechanics

摘　　要：利用首次穿越失效理论研究了在随机波浪激励下的船舶稳性。利用一组基于广义谐和函数的变换首先将船舶横摇方程降阶为一组一阶随机微分方程。接着利用一个新的随机平均程序获得了幅值过程微分方程的平均漂移和扩散系数的闭合形表达式,并建立了控制横摇幅值过程平均首次穿越时间的Pontryagin-Vitt方程。推导了Pontryagin-Vitt方程的两个边界条件,通过数值求解该边界值问题获得了平均首次穿越时间和首次穿越概率值。The first passage failure theory is applied in studying the stability of a ship under stochastic wave excitations.The ship＇s rolling equation is first reduced to a set of first order stochastic differential equations by applying a set of transformations based upon generalized harmonic functions. Then,closed-form expressions for the averaged drift and diffusion coefficients for the amplitude process differential equation are obtained by utilizing a new stochastic averaging procedure.Next, a Pontryagin-Vitt equation governing the mean first passage time of the rolling amplitude process is established. The two boundary, conditions for the Pontryagin-Vitt equation are derived, and the mean first passage time and the first passage probability density values are obtained by numerically solving the boundary value problem.

关 键 词：船舶稳性 首次穿越 随机平均 边界值问题 

分 类 号：U661.324[交通运输工程—船舶及航道工程]