Structural Performance Analysis And Partial Optimization Of The 160km/h City Car Body Structure

With the development of science and technology,people’s living standards are increasing day by day,and the requirements for the safety and comfort of traveling in transportation are becoming higher and higher.In order to make travel more convenient,and at the same time respond to national requirements for energy conservation,emission reduction,and environmental protection,we have successively developed and produced a series of urban rail vehicles.The city car is one of the more typical representatives among them.The city car not only solves the pressure of inter-city traffic between large cities,but also drives the development of the national economy.This thesis takes the car body of a middle-speed rail car as a research object and analyzes the performance of its car body structure.The content includes the following aspects:First,understand the research background of the thesis work,understand the characteristics of the car body design of different materials,study the history and overview of the development of aluminum alloy car bodies,and summarize the car body optimization methods and achievements based on different goals.Secondly,based on the theoretical basis of finite element,the mesh of the middle car body is meshed through the CAE modeling software Hyper Mesh.According to the EN12663-2010 standard,the various working conditions of the strength analysis are established,and then the structural deformation and stress distribution of the middle car body under different working conditions are calculated.According to the standard,conduct a safety assessment of the car body structure to ensure that it meets the safety performance requirements in the standard.Thirdly,the fatigue strength of the car body of the middle car of the city car is evaluated.According to the requirements of EN12663-2010,the fatigue load requirements of the vehicle body are extracted and calculated.The fatigue strength of the key components is evaluated based on the International Welding Association IIW standard,and the fatigue resistance data of the vehicle body structure is obtained.After that,study the stability of the car body structure of the middle car in the city.To study the buckling stability under compression conditions,according to the EN12663-2010 standard,the body structure of the intermediate car mainly withstands the compression conditions of the coupler in the AW3 and AW0 states and the compression conditions at the three different height positions at the ends.Determine whether the calculated linear elastic buckling factor of the whole structure under the five compression conditions meets the requirements of greater than 1.5 in the standard.The vibration characteristics of the car body are studied,and the modal analysis of the intermediate car body is carried out under the unconstrained state of the steel structure to obtain the low-order vibration frequency of the car body and determine whether it meets the standard requirements.Finally,based on the idea of light weight,the strength surplus of the compression condition of the upper side beam of the car body end under the ready condition is studied,and the weight reduction optimization analysis of the middle roof of the city car is carried out.The optimization object uses sub-model technology to cut the overall structure of the roof.After the optimization,the optimized model and the original structure are compared under the same conditions.The calculation results show that the optimized results have good strength and performance.