中文摘要：

两波浪频率(WF ) 并且低频率(LF ) 系在的紧张的部件是原则上 non-Gaussian 由于在动态系统的非线性。这份报纸进行过去常估计绳索线疲劳损坏经由的系在的紧张振幅的适用的概率密度功能(PDF ) 的全面调查光谱方法。绳索线紧张回答的短期的统计特征第一被调查，在哪个从 Gaussian 近似产生的差异被比较峭度和偏斜度系数揭示。几分布基于现在工作分析光谱方法被选择表示绳索线紧张振幅的统计分发。结果显示 Gamma 类型分发和 Dirlik 和 Tovo-Benasciutti 公式的线性联合对分开的 WF 和 LF 绳索紧张部件合适。一个新奇参量的方法然后基于非线性的转变和随机的优化被建议由于 non-Gaussian bimodal 紧张回答增加绳索线疲劳评价的有效性。把时间域模拟用作一个基准，它的精确性进一步用一个系在的半能沉入水中的平台的数字案例研究被验证。

英文摘要：

Both wave-frequency （WF） and low-frequency （LF） components of mooring tension are in principle non-Gaussian due to nonlinearities in the dynamic system. This paper conducts a comprehensive investigation of applicable probability density func- tions （PDFs） of mooring tension amplitudes used to assess mooring-line fatigue damage via the spectral method. Short-term statisti- cal characteristics of mooring-line tension responses are firstly investigated, in which the discrepancy arising from Gaussian approximation is revealed by comparing kurtosis and skewness coefficients. Several distribution functions based on present analytical spectral methods are selected to express the statistical distribution of the mooring-line tension amplitudes. Results indicate that the Gamma-type distribution and a linear combination of Dirlik and Tovo-Benasciutti formulas are suitable for separate WF and LF mooring tension components. A novel parametric method based on nonlinear transformations and stochastic optimization is then proposed to increase the effectiveness of mooring-line fatigue assessment due to non-Gaussian bimodal tension responses. Using time domain simulation as a benchmark, its accuracy is further validated using a numerical case study of a moored semi-submersible platform.