Análise estrutural dinâmica e verificação de projeto à fadiga de torres de aço para suporte de turbinas eólicas

Abstract

Wind energy has been playing an very important role in the Brazilian energy matrix, mainly especially with regard to the northeast region of Brazil. In this sense, a great technological evolution has occurred over several decades, transforming old windmills into extremely tall and slender towers, with the capacity to generate large amounts of energy. According to this context, this work and research aims to study the dynamic structural response and structural fatigue assessment (service life) of a steel tower to support a wind turbine model MM92 by Repower. In this way, a numerical model was developed to represent the investigated tower, using the ANSYS software, using the Finite Element Method (FEM). The non-deterministic dynamic analysis was performed based on the use of different wind speed profiles, in the range of 10 m/s to 70 m/s, aiming to obtain the dynamic structural response of the structure, in terms of the maximum values of the translational horizontal displacements and von Mises stresses. Bearing in mind the results of the analyzes, the values of the stresses, calculated in the permanent phase of the response of the system, will be used for the fatigue analyzes aiming at the determination of the useful life of the tower. Based on the results achieved throughout the research, it is worth mentioning that up to a speed of 35 m/s, the structural design of the tower meets the design limits established for the maximum values of the horizontal translational displacements and fot eh useful life of the tower, making the investigated wind tower project viable throughout the Brazilian territory. However, it is noteworthy that for higher wind speeds (v > 35 m/s), the design of the tower needs to be reassessed, especially with regard to structural fatigue.