Projeto estrutural otimizado de torres tubulares de aerogeradores em materiais compósito

Abstract

The wind energy is a valuable renewable energy resource, and it has been explored in Brazil, with a strong tendency to increase in the next decades, considering the Brazil's potential. The most common way to explore wind energy is through wind turbines, usually designed to have maximum energetic efficiency. The tower is an essential part of the wind turbine design, once it defines the wind turbine position and must be designed to resist to different loadings, responding for 30% of the wind turbine cost, approximately. The composite materials are an interesting choice to manufacture tubular towers of small wind turbines, because they present excellent relations between strength and weight, also between stiffness and weight, and they offer more flexibility in the structural design, in comparison with the conventional materials. This work presents a structural optimization study of tubular towers of wind turbines in composite materials, which is based on the strength of materials, the linear instability theory, and the principle of virtual work, to minimize the tower's weight. Some comparisons are made with optimized steel and aluminum towers. The minimization of the tower's weight through the employment of optimization techniques allows a reduction of the costs with materials, transportation, assembling and maintenance of the tower, with the intention to make feasible the manufacturing of composite material towers for small wind turbines, especially those ones that will be installed in remote areas with difficult access, besides contributing with the study of this technology not much explored in Brazil.