The Study On Lightweight Of Vehicle’ Frame

Steel structure dedicated trucks are the high efficient and practical equipment forthe level of horizontal handling and transport, which are used widely in many logisticsplaces, such as freight railway station, terminals, large and medium-sized shipyards,airports, large and medium-sized industrial enterprises, warehouse and so on. In orderto improve the Economical Benefit of the vehicle, lightweight carriage body is one ofthe most important means to decrease the cost of such vehicles. The transport vehiclethis paper researched is a kind of special truck，which is product by a rail transitvehicle factory. The main supporting member is the special steel structure frame. Thevehicle body frame lightweight study plays a very important role in the vehiclelightweight, and also has theoretical significance and practical engineering value.This paper’ object is special steel structure transit vehicle, around the design ofcarriage body, researched the optimization of frame and its additional structure.According to customer needs, design and calculate the body structure of special steeltruck. The CAD model of frame and affiliated special structure is set up in the CATIAsoftware; Based on the finite element method (FEM), finite element model of theframe and attached special structure is builded in Hypermesh software; Analyse thestiffness and strength of the body structure of special steel structure vehicle; Based onthe analysis of the performance, we do the lightweight optimization design; Based onlightweight result，we compared and analysis the frame structure and its affiliated, toimprove the structural characteristics and achieve the goal of lightweight, which canlower manufacturing costs, and reduce the cost.The paper based on the optimization theory, used the frame material thickness asthe design variables, the frame volume (weight) as the objective function, the framestrength and first-order natural frequency as constraint conditions, established theframe optimization mathematical model. Analysis the impact of frame materialthickness sensitivity by the frame bending stress, torsion stress and first-order naturalfrequency. Used structural optimization software OptiStruct to the sizeoptimization of frame design variables. The frame quality reduced from4205kg to4205kg, rich19%. First-order natural frequency increased from1.55Hz to1.55Hz,avoiding resonance of the use condition.Then to checked the optimized frame, validated that the frame stress distribution tends to average, and the strength and stiffness meet the requirements. The first-ordermodal frequency of frame avoid resonance frequency of the vehicle commonly usedspeed.