Fluid-structure interaction simulation of floating structure interacting with the combined effect of wave-current-earthquake based on CFD method

This study investigates the dynamic interaction between floating structures and surrounding water under combined wave–current–earthquake excitations using Computational Fluid Dynamics (CFD). A two-dimensional fully coupled fluid–structure interaction (FSI) model is developed and validated based on the incompressible Reynolds-Averaged Navier–Stokes (RANS) equations with a standard k–ε turbulence model, implemented in ANSYS Fluent. The model is used to simulate the complex dynamic behavior of a floating structure subjected to multiple hazard excitations. First, the coupled effects of waves, currents, and seismic motions on the floating structure are examined through numerical simulation. The model captures the oscillatory flow fields induced by external loads and provides detailed insights into the resulting hydrodynamic responses. The influences of wave–current interaction and earthquake–wave coupling on wave run-up and hydrodynamic pressure around the structure are specifically analyzed. Moreover, the nonlinear characteristics of hydrodynamic forces under multi-hazard conditions are discussed. Finally, a substructure analysis method incorporating fluid–structure interaction is proposed to evaluate the structural motion response under combined environmental loads. The findings provide a theoretical basis for the design and analysis of floating structures in seismically active marine environments.