Numerical Analysis of Offshore Installation Using a Floating Crane with Heave Compensator in Waves

doi:2012.26.1.70

J. Ocean Eng. Technol. > Volume 26(1); 2012 > Article

J. Ocean Eng. Technol. 2012;26(1):70-77.
DOI: https://doi.org/10.5574/KSOE.2012.26.1.070

Nam Bo-Woo,Hong Sa-Young,Kim Jong-Wook,Lee Dong-Yeop

Marine Stucture & Plant Research Department KORDI,Marine Stucture & Plant Research Department KORDI,Maritime Research Institute Hyundai Heavy Industries Co.,Chungnam National University

Heave Compensator를 고려한 파랑 중 해상 크레인 설치작업 수치해석

남보우,홍사영,김종욱,이동엽

한국해양연구원 해양구조물.플랜트연구부,한국해양연구원 해양구조물.플랜트연구부,현대중공업 선박해양연구소,충남대학교 선박해양공학과

Keywords: Floating crane, Heave Compensator, Wave-induced motion, Tension, Lowering simulation

핵심용어: 해상크레인, 상하동요 저감장치, 파랑운동, 장력, 하강 시뮬레이션

Abstract

In this study, a numerical analysis of offshore installation using a floating crane with heave compensator is carried out in time domain. The motion analysis of crane vessels is based on floating body dynamics using convolution integral and the crane wire is treated as simple spring. The lifted structure is assumed as a rigid body with 3 degree-of-freedom translational motion. The heave compensator is numerically modelled by the generalized spring-damper system. Firstly, forced motion simulations of crane wire system are carried out to figure out the basic principle of heave compensator. The transfer function of crane wire system is obtained and effective wave period of heave compensator are found. Then, coupled analysis of crane vessel, crane wire, and lifted structure are performed in regular and irregular sea conditions. Two different crane vessels and two lifted structures (suction pile and manifold) are considered in this study. Through a series of numerical calculations, the effective zone of heave compensator is investigated with respect to wave period and crane wire length.