The Impulse Response Function and Motions of Floating Body

为了精确地模拟海洋系泊结构在波浪和（或）逐级风力共同作用下的运动，在时域模拟中经常使用带有记忆效应函数的卷积积分方程。因此，在本研究中，对以下受试者进行了调查。1)卷积积分方程中涉及的脉冲响应函数（记忆效应函数）的近似求值方法。2)用1)的方法评估了系泊海洋结构体在波浪中运动的记忆效应函数时域模拟的有效性。3)强迫振荡试验记忆效应函数的估计方法。从目前的研究中，发现了以下结果。1)在高频区域用三角形逼近被积函数可用于记忆效应函数的评价。2)用卷积积分方程对系泊半潜式平台运动进行时域模拟，结果与实测结果吻合较好。(3)用受迫振荡试验的实测数据计算的记忆效应函数与用(1)方法计算的记忆效应函数有较好的一致性。为了得到更准确的结果，还需要进一步的研究。

In order to obtain the precise results of the motions of a moored ocean structure under the combined action of waves and/or stepwise wind force, the convolution integral equation with the memory effect function in the time domain simulation are frequently used. Therefore, in this study, the following subjects are investigated.1) Approximate evaluation method for the impulse response function (memory effect function) which is involved in the convolution integral equation.2) Validity of the time domain simulation for the motions of a moored marine structures in waves with the memory effect function evaluated by the method of 1).3) Estimation method of the memory effect function from the forced oscillationtests.From the present study, the following results are found. 1) An approximation of the integrand at high frequency region by a triangle is to be applicable for the evaluation of the memory effect function.2) Time domain simulations using the convolution integral equation for motions of a moored semi-submersible platform show a good agreement with the measurements.3) The memory effect function evaluated from the measured data in the forced oscillation test show somewhat good agreement with the one obtained by the method of 1). In order to more accurate results, further investigations are needed.