전달함수를 이용한 부유식 해양구조물의 저주파 진동 해석

Abstract

불규칙파에 의한 부유식 해양 구조물의 진동에는 2차 비선형성이 주된 역할을 한다고 알려져 있다. 2차 비선형성이란 2개의 주파수 성분이 상호작용하여 그 합 혹은 차의 주파수 성분이 결과로서 생기는 경우인데 볼테라 급수를 이용하여 이러한 2차 비선형성의 커플링(coupling) 현상을 해석하였다. 본 논문에서는 불규칙 해상에서 해양구조물의 진동을 해석하기 위하여, 불규칙파를 입력으로 하고 해양구조물의 진동을 추정하고, 불규칙파에 의하여 부유식 해양 구조물에서 생기는 3개의 주파수 성분의 커플링 ?恥瓚? 해석하였다.

One of the examples of the three-wave coupling phenomena is the low-frequency oscillation of floating sea structures. The second-order Volterra series, which is one of the the simplest Volterra series, is used in order to analyze the three-wave coupling phenomena ins the second-order nonlinear system. The objects of this research are (1)the analysis of the oscillation of the floating sea structure by using the estimation of the linear transfer functions and the quadratically nonlinear transfer functions of the structure of which the input is the random waves and of which the output is the oscillation of the structure and (2)the analysis of the three-wave coupling phenomena by using the transfer functions.

One of the examples of the three-wave coupling phenomena is the low-frequency oscillation of floating sea structures. The second-order Volterra series, which is one of the the simplest Volterra series, is used in order to analyze the three-wave coupling phenomena ins the second-order nonlinear system. The objects of this research are (1)the analysis of the oscillation of the floating sea structure by using the estimation of the linear transfer functions and the quadratically nonlinear transfer functions of the structure of which the input is the random waves and of which the output is the oscillation of the structure and (2)the analysis of the three-wave coupling phenomena by using the transfer functions.