Aplicação de algoritmos genéticos na otimização de placas laminadas tipo sanduíche

Abstract

Composite materials largely used in aeronautical and aerospace industry are receiving considerable attention from oil and gas industry due to their favorable structural characteristics, as high strength/weight and stiffness/weight ratios and good corrosion resistance and fatigue life. Other important advantage is their taylorability that permits to design materials to resist applied loads in an efficient way. A common type of composite materials is the laminated composite that consist of layers with different properties bonded together. A sandwich material is a special case of laminated comprising a core of one material between two layers of another material. However, the design of a composite structure is more complex than the metallic one (i.e. homogenous) due to the large number of design variables. The application of traditional design process (try and error) can be cumbersome. A design can be achieved using numerical optimization techniques by formulating the problem as a search for design variable values that minimize an objective function and satisfy imposed constraints. Sometimes, design variables assume only discrete values and objective and constraints functions may be no differentiable and not continuous. Genetic algorithms (GAs) have been applied to overcome these issues. They are based on simulation of the Darwin’s Evolution Theory and Genetic concepts. They seem proper to optimization of laminated composite structures. In this work, the application of GAs to a composite sandwich plate is investigated and compared with classical mathematical programming results. This successful use has stimulated the application of GAs to design laminated fiber-reinforced composite materials that can be used in tubes and risers.