Numerical analysis of the dynamic response of a single-point mooring fish cage in waves and currents

Abstract

In this study, we developed a numerical model of a single-point mooring (SPM) cage system based on the finite element method, and employed it to simulate the dynamic response of the cage system under conditions with waves and currents. We focused mainly on the mooring line tension and deformation for the cage collar. The simulated results indicated that adding a buoy as part of a cage system was helpful for reducing the force and deformation of the cage collar, and the current contributed greatly to the total load on the cage system. In addition, the location of the greatest deformation of the cage collar was confirmed by comparing the stress results for different points in the collar structure when exposed to strong waves and current. Therefore, to avoid plastic failure, we tested a connected component with a lower pipe diameter to wall thickness ratio to effectively reduce the deformation of the floating pipes, thereby enhancing the security of the SPM cage system under severe sea conditions. Furthermore, we analyzed and discussed the effects of the material characteristics on the dynamic properties of the SPM cage system.