FEA And Structure Optimization Of One Commercial Bus Frame

Frame is the main loading component of automobiles, its design has been highly regarded bycarmakers at home and abroad. On the basis of analyzing and researching the advanced designmethods and current design situation of frame abroad, this paper, taking the frame of adomestic bus as the prototype, carried on optimum design to the frame based on design methodsderived by optimization.First, starting from the original frame, its stiffness、strength and modes were analyzed.Analysis showed that its strength and dynamic behavior satisfied the design requirements. Theresults of FEA of the frame verified the frame’s design and at the same time, provided thefoundation for the following research.Later, according to the trim size, the base model of topology optimization of the bus framewas built. Regarding the maximum stiffness under several working conditions as the aim, andthe volume fraction as the constraints, the topology optimization of the base model wasconducted and the reasonable discrete arrangement of frame materials was got under theconsideration of manufacturing engineering constraints；in accordance with the result oftopology optimization, the frame was redesigned and new model was obtained. At the basis ofthis, with an objective of minimizing the mass, the size optimization of the frame was conductedfor lightweight on the premise that the stiffness performance was not reduced.The results of the study showed that after topology optimization and redesign, the newframe’s first step frequency was increased by4.5%, its bending stiffness was increased by25.6%,its front torsion stiffness and rear torsion stiffness were respectively increased by0.6%and0.3%while its mass was decreased by7.2%.The effects of the optimization is obvious.Topology optimization put forward by this paper is feasible, it gives a new thought for thefuture frame design and has good application value.