Characteristics of the Wave Slamming Forces on Jacket Structures Under Plunging Breaking Waves Based on Experimental Data

Abstract

Due to increased energy demand and thrive for clean energy, offshore wind energy has become popular these days. A large number of offshore wind turbines supported by fixed type substructures have been installed, among which jacket structures are getting popular in recent times. The forces from breaking waves are a major concern in the design of offshore structures installed in shallow waters. However, there are only limited studies available regarding breaking wave forces on jacket structures and still there exist many uncertainties in this area. During the WaveSlam experiment carried out in 2013, a jacket structure of 1:8 scale was tested on a large number of breaking wave conditions. Wave properties and the forces on the structure were measured during the experiment. The total wave slamming forces are being filtered from the experimental measured force using the Empirical Mode Decomposition method and local slamming forces are obtained by the Frequency Response Function method. Based on these results, the peak slamming force and slamming coefficients on the jacket members are estimated. The wave parameters (wave height and period) and wave front asymmetry are obtained from measured wave properties. The variation of slamming forces and slamming coefficients with respect to these parameters are also investigated.