推导出线性条件下深水立管的动力响应与有义波高之间的关系，并对其进行了非线性修正．据此采用时域缩放的方法得到立管的动力响应，进而进行疲劳分析，并与精确方法的计算结果进行了比较．结果表明，采用线性缩放计算得到的疲劳寿命较为保守，而采用指数缩放的结果更优，其误差在工程上可接受的范围之内．该方法可隐性考虑系统响应非线性的影响，且只需计算少量海况即可得到较为满意的结果，可以用来进行初始设计阶段立管的疲劳分析及疲劳参数的敏感性分析．在疲劳校核阶段，该方法依然适用，以最大有义波高下的响应作为基准进行缩放保证了计算结果的保守性．

In this paper,first,the relationship between the dynamic response of the deepwater riser and the significantwave height is deduced under a linear assumption,and a correction is further made to allow for nonlinearity.Then,the dynamic response of the riser is obtained by employing the time-domain scaling method,based on whicha global fatigue analysis is performed. Finally,the results are compared with those obtained by the accurate calculationmethod. It is shown that ( 1) the power-law scaling approach achieves a fatigue life more acceptable in industrywhile the linear scaling approach is more conservative; ( 2) the proposed method takes into consideration thesystem nonlinearity implicitly and helps to obtain accurate results with less computational effort,so that it is suitablefor the initial assessment of riser fatigue and the sensitivity analysis of predicted fatigue life to key input parameters;and ( 3) the proposed method is also suitable for the fatigue evaluation due to its conservatism guaranteed by thescaling from large to small significant wave heights.