A Study on the Analysis of Multi-let Spread Mooring Systems

J. Ocean Eng. Technol. 1995;9(2):53-60.

Sin Hyeon-Gyeong,Kim Deok-Su

다점지지 계류시스템의 정적해석에 대한 연구

신현경,김덕수

울산대학교 조선 및 해양공학과,울산대학교 조선 및 해양공학과

Keywords: Floating Offshore Structure, Multi-leg Spread Mooring System, Static Analysis, Runge-Kutta 4th Method, Spring Constant, Taylor's Series Expansion

핵심용어: 부유식 해양 구조물, 다점지지 계류계, 정적해석, 룽에-쿠타 4차법, 스프링 상수, 테일러 급수 전개

Abstract

A multi-leg spread mooring system for floating offshore structures is important, but the multi-leg static analysis is complicated due to the nonlinear behavior of each line and the effect of current which affects each line differently. The pretensioned position of the multi-leg mooring system obtained from the static equilibrium condition changes into a different position due to external loads and current. In this paper, the new position and the static tension at each line are caculated. The relation between the initial static equilibrium position and the new position due to the external loads is expressed in terms of the Taylor's series expansion. The Runge-Kutta $4^{th}$ method is employed in analyzing the 3-dimensional static cable nonlinear equations.