Hydrodynamic response analysis of a 10,000-ton offshore electrical platform in waves using a modified finite element model

Abstract

The electrical platform in offshore wind farm is prone to fatigue and damage in wave loads, which will threaten the safety and reliability of the structure. In this study, through the least square fitting analysis of the hydrodynamic response of the jacket structure from the physical model test, the hydrodynamic coefficients considering the blockage effect of the complex jacket structure were obtained. Thus, the finite element model of the platform was improved in the simulation of fluid-structure interaction. On this basis, the response results of the strain, acceleration, displacement and support reactions of the platform at three typical attack angles of regular waves were calculated. The results indicated that the hydrodynamic responses of the platform along the elevation are significantly affected by the heavy superstructure. Thus, the acceleration and displacement results present a trend that the farther away from the water surface, the smaller the response is. While the strain response has a maximum value near the water surface and the bottom of jacket. In addition, the responses increase rapidly with increasing wave height and variate obviously in different wave directions. Therefore, the responses caused by the external environmental load and wave height in different directions should be fully considered.