A general linear hydroelasticity theory of floating structures moving in a seaway

TLDR

Linear hydroelastic theory is well established for simple beams but cannot readily be extended to complex shapes such as semi‑submersibles or fixed offshore platforms. The paper proposes a general finite‑element method that incorporates any 3‑D elastic structure into a linear hydroelastic framework. The method uses sinusoidal wave excitation and fully three‑dimensional fluid flow to model the interaction with the structure. Illustrative examples demonstrate the theory’s applicability and reveal previously unseen hydroelastic behaviours.

Abstract

The dynamics of an elastic beam floating on the surface of disturbed water has formed the basis of a fairly comprehensive linear theory of hydroelastic behaviour of ships in waves. The existing theory cannot easily be extended to floating vehicles of more complicated shape (such as semi-submersibles), or to fixed offshore structures. A general method is presented, by which finite elements permit any three-dimensional elastic structure to be admitted in a linear hydroelastic theory. Sinusoidal waves provide the excitation of the structure and the fluid flow is three-dimensional. Some examples are given which illustrate the use of the theory and expose behaviour that has not been encountered hitherto.