Analysis of Offshore Wind Turbine Towers with Different Designs by Finite Elements Method

Abstract

It is known that the use of renewable energy has an increasing trend in whole world. Wind energy is one of the renewable energy types, as well is among the cleanest and most economical energy sources. Nowadays, in order to provide much more energy from wind, turbine towers are being built higher and the turbine blades have begun to be manufactured longer. Due to these applications, tower and turbine weights are continuously increasing. For this reason, it is necessary to optimize the materials used as well as the dimensions of the turbine towers. In the present study, behavior of TLP floating wind turbine towers with three different designs under wave, hydrostatic and static loads were investigated. In order to clarify the effect of these loads, turbine designs were analyzed in the ratio of 1/5 using finite elements method. Steel, reinforced concrete and hybrid (reinforced concrete and steel) wind turbine towers tied to sea floor at a depth of 10 meters rigidly by TLP floating method. In this context, 10-meter-high turbine towers having three different designs which static analyzed previously were used for investigate effects of wave and hydrostatic loads. Turbine structures analyzed with ABAQUS finite elements model. The deformations and stress values of underwater turbine structures were obtained and compared with each other. As it can be seen from analysis results, compared to the reinforced concrete design, the displacement of steel tower design decreased 77.84%. It is seen that the torsion effect was dominant in the steel tower design. However, the decreasing displacement value for steel design was recorded as 44.43% compared to the hybrid tower design.

Fatigue life analysis of offshore wind turbine tower under combined action of wind and wave

“…Considering that the construction and operation costs of offshore wind turbines are higher than those of onshore wind turbines, it has become a trend to develop ultra-large power offshore wind turbines. Offshore wind turbine tower is subject to the combined action of wind load and wave load at the same time, and the stress situation is more complicated than that of onshore wind turbine, so it is necessary to calculate the environmental load in detail [1][2] and carry out the design technology research of the tower to improve its working performance [3][4][5]. In addition, the operation and maintenance cost of offshore wind turbine is higher than that of onshore wind turbine.…”