Shape optimization application for weight reduction of a container wagon

Abstract

In this study, shape optimization method is applied to a container wagon for the reduction of its weight. Railway transportation is an important place among the other transportation methods, especially for large and bulky freights. Different kind of freights can be carried by different type of wagons that have their own design characteristics. Container wagons are one of them, too. Test procedures are determined according to the international standards for each type of wagon. The weight of a wagon should be reduced to increase the loading capacity and provide a significant cost reduction. Weight reduction can be accomplished in two ways, making a new design or modifying an existing design. Making a new design costs much more than modifying. So second way is usually preferred. The best way for the modification of a design is using optimization techniques. First step is solid modeling of wagon. Then, this model is divided into finite elements. Loading and boundary conditions are defined with reference to international standards. Analysis results are compared and most critical load case is chosen. Stress and vertical displacement value are used for the determination of most critical load case. Optimization formulation is generated according to this load case. Optimization results do not provide a sufficient weight reduction. But, these results provide insight about how to minimize the weight more and which modification can be done for the future works.