Hydroelastic Buckling Behaviours of Circular Fish Pen Under Waves

Abstract

Open-sea aquaculture has become a sustainable and reliable food source, which offers larger open areas and better water quality for fish farming. This study aims to investigate the buckling behaviour of circular fish pens under wave conditions, a significant step in ensuring the structural integrity of fish pens. The study used the finite element method (FEM) software package to analyse the buckling behaviour of the circular fish pen under various environmental conditions and design options. The buckling factor was used to determine the buckling behaviour of the structure, which was calculated based on the compressive axial force, and the Euler buckling equation was used to calculate the critical buckling load, which includes the structural component movement and material properties. The results show that the floating collar of the circular fish pen when designed with constant parameters, is prone to buckling under higher wave heights and frequencies. Parametric studies were also conducted to evaluate how different design options could affect the buckling behaviour of the floating collar. Increasing anchor line pretension and submerging the cage structure to greater depths effectively improves the buckling bearing ability of the floating collar. However, increasing the cross-section area of the High-Density Polyethene (HDPE) pipe used for the floating collar would lead to a buckle. This research will provide helpful references for engineers to design floating fish cages.

Keywords: Numerical FEM, circular fish pen, dynamic response, structure buckle