Optimization Design On Long Flat Vehicle Structure

With the continuous development of China’s industrialization process,metallurgy,electric power,petroleum chemical industry and military equipment etc.got the rapid development,and railway transportation is chosen by more and more large equipment with large volume and complex shape.Long freight trains can meet transport requirements of these special goods because of its structural features,and long flat vehicles are belong to the trains.The long flat vehicle studied in this paper is used to transport heavy wheeled transport truck.Considering the vehicle axle load limit and transportation cost,the vehicle weight should be reduced as much as possible at the same time the strength meets requirement..So the lightweight of vehicle body becomes an urgent research topic.The topology and size optimization is implemented based on the analysis of static strength and fatigue strength for a long flat vehicle body.First,the finite element model of the vehicle body is established by HyperMesh software,and load steps are applied according to the actual application and relevant norms.The static strength analysis is executed with Radioss software.Secondly,the fatigue strength analysis of the dangerous parts for the vehicle body is carried out with the BS standard and load spectra in the AAR standard.Then,the displacement and stress sensitivity of the key plate structure is analyzed.The topology optimization model of the main plate structure is determined based on the sensitivity results and the topology optimization is actualized by OptiStruct solver.The new design of the body structure is given based on the result of the topology optimization,and the static strength and fatigue strength is checked.Finally,the displacement and stress sensitivity of the main plate structure is analyzed for the topology optimization structure to search suitable design variables,and the reasonable size optimization model is proposed.The size optimization is carried out with Optistruct solver,and the static strength and fatigue strength of the optimal structure is checked again.A combination of topology optimization and size optimization is implemented to realize structure optimization design of the long flat vehicle,and the body weight is reduced 3.9t while the body strength is ensured.Lightweight of the vehicle body is achieved well.