中文摘要：

以浅水单点系泊装置水下软钢臂维修解脱为背景,研究在拖轮限位状态下FPSO运动与限位缆绳张力。计算在不同水深及浪向条件下,FPSO的二阶传递函数（QTF）;分别应用Newman近似方法、全QTF法以及使用部分QTF值的方法,计算FPSO时域低频波浪载荷,并对其限位响应进行对比;计算不同长度时的限位缆绳张力响应,分析限位缆绳长度及FPSO波频运动对缆绳张力的影响。分析表明：Newman近似的适用性,应根据FPSO的QTF与海浪谱能量集中范围综合判断;为减少QTF计算量,可根据FPSO低频运动固有频率,确定频率间隔△ω的计算上限,采用部分QTF值计算低频波浪载荷,其响应预报结果与全QTF法接近;若FPSO的RAO能够避开海浪谱能量集中的频率范围,则在限位分析中可忽略FPSO波频运动的影响。

英文摘要：

Taking the disassembly operation of SPM in shallow water as background, the motion of FPSO and the tension of wire rope are calculated and studied. Quadratic Transfer Functions （QTF） of the FPSO at different depths and in different directions are calculated . And the low frequency wave loads are calculated respectively with Newman approximation, Full QTF and partial QTF values, then the responses calculated in time domain are compared. The influences of wire rope length and wave frequency motion of FPSO on the tension results are also analyzed. It is found that the applicability of Newman approximation depends on the QTF and the frequency range of the wave spectrum, and both should be taken into consideration. For reducing the calculation cost, the max. difference frequency can be determined according to the natural frequency of FPSO and only partial QTF values are needed to calculate the low frequency wave loads; and the time domain results are close to those using Full QTF. If the frequency range of the wave frequency motions＇ RAO is apart from that of wave spectrum, the influence of the wave frequency motion of the FPSO can be ignored in the position limiting analysis.