DYNAMIC PRESSURE ON A FLOATING PLATFORM DUE TO SURFACE WAVES

Abstract

Floating platforms serve a wide range of strategic and functional purposes, including offshore infrastructure for industrial operations and oil exploration, as well as civic applications such as floating airstrips and recreational parks. They are also critical in defence sectors, particularly for naval bases and mobile support systems. Given their exposure to dynamic environmental forces, especially wave action, understanding their structural response is essential for safe and efficient design. In this study, the behaviour of a rectangular floating platform is examined under hydrodynamic loading. The platform is assumed to float on an infinitely extended fluid domain with finite depth, which reflects realistic ocean conditions where lateral boundaries have negligible influence but depth remains a governing factor. The problem is treated as a coupled fluid–structure interaction system, where the fluid domain is modelled in three dimensions using pressure as the primary nodal variable, while the platform is represented as a two-dimensional structural element characterized by displacement. To accurately capture the mechanics, the platform behaviour is modelled using Mindlin plate theory, which accounts for transverse shear deformation and is suitable for moderately thick plates. The fluid motion is governed by the Navier–Stokes equations, simplified under the assumptions of incompressibility and inviscid flow to focus on dominant pressure effects. The base of the fluid domain is considered perfectly rigid, ensuring complete wave reflection without energy dissipation—an assumption that helps isolate the impact of wave-structure interaction. The resulting time-dependent coupled equations are solved using Newmark-beta method, which provides stable and accurate solutions for dynamic systems. Dynamic pressure acting on the platform is evaluated, and the additional stresses induced by wave action are quantified in terms of bending moments. These are further expressed as non-dimensional coefficients, offering practical utility for engineers to estimate bending responses efficiently in design applications.