Inundation effect of wave forces on jack-up platforms

Abstract

This paper aims to study the importance of the wave inundation effect. A concentrated force acting at the mean water level of the platform leg is used to represent the inundation effect due to variable wave surface. Its effects on the total and maximum wave forces are investigated based on structural modal analysis and linear wave assumptions. After the inundation drag force is approximated as an asymmetric second-order term, the corresponding frequency-domain transfer functions of Volterra/Wiener representation are derived. The auto-spectra of the deck displacement of 2 typical jack-up platforms are numerically evaluated to show the significant contribution of the inundation effect to the structural dynamic responses.