OPTIMIZED STRUCTURAL DESIGN OF TUBULAR TOWERS OF WIND TURBINES IN COMPOSITE MATERIAL

Resumo

The wind energy is an important renewable energy resource, and it has been recently explored
in Brazil, with a strong tendency to increase in the next decades, considering the Brazil's potential. The
most common way to explore the wind energy is through the wind turbines, usually designed to have
the maximum efficiency. The tower is an important part of the wind turbine design, once it defines the
wind turbine efficiency 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 great relations between strength and weight,
and 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, within a framework based on the strength of
materials and the principle virtual work for the structural analysis of the tower, besides optimization
techniques, with the goal 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 inputs, 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.