The Structual Optimization Of A Three-Piece Bogie Of Freight Car

The railway freight car’s feature of heavy load and long marshalling which puts forward a higher request for its running safty, bolsters and side frames as the key components of railway freight car bogie bear the impact load of all directions while running, the structure and mechanical properties of them directly affect the life and running safety of bogie. Therefore, in the conceptual design phase,base on the theory of structural optimization and mathematical method, with the aid of computer and engineering software, making a structural topology optimization on bolsters and side frames to achieve the purpose of improving their structure mechanics performance and reducing their weight.This paper based on bolsters and side frames of a certain three-piece bogie of freight car, firstly, makes a static strength and rigidity calculation analysis of the original model, according to the calculation results, determining their design area and selecting the main load cases for structural topology optimization, then on the basis of optimization results, combineswith the factors of actual production technology level and running function, makes a secondary design for the structure of bolsters and side frames respectively, fianlly providing two design schemes for bolsters and a design scheme for side frame.Making a static strength and rigidity calculation for Bolsters and side frames of the secondary design scheme, comparing the optimized results with the original. The calculation results show that on the two optimization design schemes of bolsters and a optimazation design scheme of side frames, the maximum Von Mises stress and the maximum displacement of each calculation load condition can satisfy the requirements of static strength and stiffness. The stress contour displays that stress distribution of the secondary design scheme is more uniform and structure is more reasonable which improves the performance of structural mechanics and reducing self weight, the first design scheme of bolster reduces weight of37kg, the second design scheme of bolster reduces weight of41kg, the corresponding weight loss rate are8.6%and9.7%; the design scheme of side frame reduces weight of15kg, the corresponding weight loss rate is4.6%.To sum it up,by making a topological optimization design for bolsters and side frames,this paper puts forward a new design scheme which can improve the overall mechanical properties of them and reduce their self weight. The research results provide references for the design of bolsters and side frames of railway freight car.