| Nowadays,with the rapid development of the economy of our country,the urban population has increased significantly and the number of motor vehicles has risen sharply.This situation has led to the increasingly prominent problems of traffic congestion and environmental pollution,which has largely restricted the development of urbanization in China.Therefore,due to the balance of efficiency and cost performance,urban rail transit has gradually become the optimal solution for this problem with its unique advantages such as large traffic volume,high speed,safety,environmental protection and resource conservation,and it has developed rapidly in many cities in China.However,the continuous increase of total operation mileage and vehicle configuration of the subway has brought about the fact that the income and expenditure of the urban rail transit can not always reach a balance and the energy consumption has increased tremendously,which has long restricted the healthy development of urban rail transit.In order to find solutions to the problems,higher requirements are put forward for the manufacturing cost and safety of Metro based rail vehicles.In this thesis,the development process of aluminum alloy car body at home and abroad and the research status of simulation analysis of the car body structure is described.Based on the standards of EN12663-2010,TB/T3115-2010,IEC60300-3,the strength,stiffness,mode and fatigue of a B-type aluminum alloy subway car body of Nanjing subway under various loading conditions is comprehensively simulated and analyzed by using finite element analysis software such as Abaqus,Hypermesh,Fe-safe and Optistruct.Finally,based on the theory of full life cycle cost,the size optimization for the plate thickness of the body structure profile is carried out,which reduces the overall quality of the body and the production cost.The main research contents of this thesis are summarized in the following parts:(1)In the second chapter of this article,the three-dimensional model of the B-type aluminum alloy car body was established in Catia software and imported into Abaqus and Hypermesh finite element analysis software to simplify the model,including the simulation of the connection method and the quality of accessories,and then the mesh is divided.(2)Based on the EN12663-2010 standard,in the third chapter of this article,the static strength of the car body is analyzed by using Abaqus software under three categories and ninecalculation conditions.The calculation results show that the maximum Von-Mises of each part of the car body under each working condition is less than the yield strength of the corresponding material and there is a certain margin,indicating that the car body can be further optimized in size.At the same time,based on TB/T3115-2010 standard,free modal analysis of the performed car body is carried out in order to ensure that the stability,safety and comfort of the vehicle operation.(3)In the fourth chapter of this article,based on the IIW standard and Miner's cumulative fatigue damage theory,four fatigue conditions are selected.By using Fe-safe fatigue analysis software,the fatigue strength of six fatigue assessment points of the car body is analyzed and the corresponding life cloud diagram is obtained.The results show that the fatigue life meets the requirements of the code.(4)Based on the theory of full life cycle cost,the fifth chapter of this thesis uses the optimization software of Optistruct to optimize the size of the car body structural profile plate thickness,and then checks the static strength,modal and fatigue strength of the optimized car body.In order to reduce the overall mass of the car body,and at the same time significantly reduce the life cycle cost of aluminum alloy car body. |
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