Abstract
Keywords - bus, weight, torsion stiffness, optimization, genetic algorithms
Nowadays, significant efforts have been carried out by bus manufacturers in order to reduce bus production costs. In this investigation the weight of the beams of the bus structure have been optimized. However, bus safety and handling may be penalised if during the weight reduction process, stiffness is not considered. Therefore, in this investigation weight optimization has been carried out in a real bus structure taking into account torsion stiffness. In the first place a finite element model of a real bus structure has been created. A finite element model has been carried out in Ansys by means of a parametric file that allows changing beam thickness. Optimization has been carried out by means of a genetic optimization tool provided with Matlab. However, Ansys and Matlab are different software and because several iterations were needed to achieve a solution, a new file management process was developed. Because of computer costs, a sensitivity analysis was first employed to identify the beams in which a change of its thickness was more important in terms of torsion stiffness. Finally, the optimization process was carried out in those beams.