Hydrodynamic response and energy analysis in a very large floating structure supporting a marine airport under typhoon-driven waves

Abstract

Very large floating structures (VLFSs) can be used to support offshore airports and seaports. Most existing studies on VLFSs have analyzed the dynamic responses of their rigid modules with flexible connections under regular sea conditions. None have examined the hydrodynamic response characteristics of flexible marine airports under typhoon-driven waves. For this, a novel method is proposed to model a flexible module rigid connection (FMRC) VLFS. The measured wave spectrum of Typhoon Megi was finely simulated using Jonswap spectral characteristic parameters. The overall and local hydrodynamic response characteristics of the VLFS under typhoon-driven waves were analyzed, and the mechanisms of energy conversion between the airport and environmental loads were determined. The FMRC model was found to accurately model the hydrodynamic responses of VLFSs. The responses were significantly nonlinear due to structural flexibility and the inhomogeneity of the typhoon loads and wave field. Displacement, rotation angle, and hydroelastic deformation of marine airport occurred mainly along the flow direction, spanwise direction, and vertical direction, respectively, with extreme stress mainly distributed near the VLFS's struts. The environmental load energy and structural gravitational potential energy were mainly converted into potential energy of the moorings in the initial stage of typhoon-driven waves, and structural kinetic energy and elastic potential energy in the stable stage of marine airport.