Contribuição ao desenvolvimento de uma estrutura veicular tipo spaceframe usando o método dos elementos finitos e métodos heurísticos de otimização numérica

Abstract

The main purpose of this work is based in a contribution to the development of the design and construction of a 3-D Spaceframe vehicle structure. Vehicle structures require the use of modern computational tools that guarantee approached solutions for the problem, since in this case the use of classic analytical solutions is not applicable. The work has as main objective the determination of an optimal chassis configuration that takes care of the requirements of low weight and high torsional stiffness by means of a commitment solution. The Finite Elements Method (FEM) has been used for modeling the structure through of the commercial software ANSYS®. It was defined primarily a geometry, a discrete model by means of bar elements and application of a static linear analysis for the calculation of the chassis torsional stiffness as well as its initial mass. This initial configuration was submited to Heuristic Methods of Numerical Optimization, aiming to the design evolution and the optimal configuration search. The Ant Colony Methods (ACO), Particle Swarm (PSO) and Genetic Algorithms (GA) had been applied to four types of formulations. Good results were obtained when using PSO Method for the case where the mass and stiffness had been taken as inequality constraints. The mass of the final design presented 35% reduction when compared to the initial value and its stiffness is 62% greater than this reference. These results lead future perspectives for this work with the use of different optimization strategies, as well as the construction of the real structure.