Design Automation of Mooring Systems for Floating Structures

Mooring systems are widely used for the station keeping of floating structures in order to maintain its position at a specified location with allowable offset limits under given environmental conditions. A well designed mooring system should have good station keeping ability, satisfy the relevant safety requirements under both operational and survival conditions, low construction, installation and maintenance costs etc. However the mooring design process involves large number of mooring layout and parameter variations, and subsequent numerical simulations. The whole process is prolong and labor intensive, and is heavily dependent on the designers’ experience. An attempt has been made to develop an automated methodology and software tool that can be used to generate an initial and feasible mooring system design automatically on the basis of the user defined boundary conditions and constraints. This paper presents the initial progress achieved in the study of the automated mooring design methodology. The Genetic Algorithm for optimization is adopted in the study to obtain the optimal solution of the objective function. In order to prove the efficiency and applicability of the automated optimal design procedure, a single point mooing system for a FPSO and a spread mooring system for a semi-submersible platform are designed using the proposed method and then analyzed in time domain in different environmental conditions. The results indicate that the proposed automated design method can be used to create a feasible mooring system design which satisfies the requirements on mooring line tension and structure offset.