中文摘要：

基于现代断裂力学方法建立立管疲劳失效的极限状态函数.应用经典响应面法求解可靠性指标时,发现迭代过程会出现混沌或数值振荡现象.为避免可靠性指标计算过程中不收敛问题,引入混沌控制方法改进算法.研究表明改进的响应面法具有较好的适用性和收敛性.基于改进的响应面法重新计算立管的疲劳可靠性指标,有效解决了迭代不收敛问题,且计算结果具有较高精度.在此基础上,分析了随机变量变异系数对立管疲劳可靠性的影响.计算结果显示立管疲劳可靠性随随机变量变异系数的增大而减小,并且随机变量B变异系数对立管疲劳可靠性的影响最大.

英文摘要：

The limit state function of riser fatigue failure was established based on modern fracture mechanics method.When the reliability index was solved by the classical response surface method,the phenomenon of chaos or numerical oscillation occurred in the iterative process.In order to avoid this problem in the calculation of reliability index,the chaos control method was introduced to improve the algorithm.Studies show that the improved response surface method has good applicability and convergence property.Based on the improved response surface method,the fatigue reliability index of the riser was recalculated,and then the problem was solved effectively with high accurate results.Then,this method was used to analyze the influence of the variation coefficient of random variables on fatigue reliability.The fatigue reliability of the marine riser decreases with the increase of variation coefficient of the random variables,and the variation coefficient of the random variable B has the greatest influence.