| At present,China’s railway capacity tension has been basically alleviated,and the bottleneck restricting the development of China’s railway industry has been basically eliminated,which meets the urgent needs of the healthy development of socialist economy.However,there are still some shortcomings in China’s high-speed railways,among which the outstanding problems are the imperfect road network layout,unbalanced regional layout and lack of electrified lines in some areas.According to the actual situation at the present stage,the design of centralized power internal combustion EMU is more in line with the needs of people at the present stage.With the key technologies of 3000 k W D180-16 V high-speed diesel engine,main and auxiliary integrated AC drive system,microcomputer controlled braking system and so on,the maximum operating speed is 160km/h,which can better solve the problem of tight passenger flow in China’s railway trunk and branch lines,improve the efficiency of railway passenger transport,bring huge economic benefits and improve the travel conditions of the broad masses of the people.As the locomotive body structure is the load-bearing part of the locomotive,the strength and rigidity of the locomotive body steel structure is one of the important indexes of locomotive operation safety.In locomotive design,it is a major consideration to study the influence of stress and deformation of locomotive body steel structure on locomotive running.The work of this thesis includes the following parts:(1)According to the overall equipment layout and the requirements of installation and positioning of related equipment,the steel structure of the centralized diesel EMU is preliminarily designed,and the finite element structural model of the car body steel structure is established by ANSYS software.The finite element analysis method is used to preliminarily calculate and analyze four typical working conditions of car body steel structure.According to the preliminary calculation structure,the unreasonable parts in the original structural design are effectively optimized and improved,so that the structural design is more perfect.According to the requirements of BS EN 12663-1:2010 and TJ/JW 102-2017,the stress analysis of the finally improved structure under 23 static strength calculation conditions was carried out.The first-order modal vibration analysis of the prepared car body is completed to verify whether the designed car body in the prepared state resonates with other main vibration sources.(2)The integrated suspended fuel tank is adopted in the power concentrated internal combustion EMU,and the fuel tank does not participate in the whole vehicle load.However,the fuel tank,as an important component in the locomotive running process,needs to be checked by finite element analysis in order to avoid the strength problem in the operation process.After finite element analysis,the maximum stress of the fuel tank structure is less than the allowable stress,which indicates that the static strength meets the relevant requirements of BS EN 12663-1:2010 standard.Goodman-Smith fatigue limit diagram is adopted for fatigue strength assessment of oil tank.Through the fatigue analysis of the fuel tank,the maximum and minimum stress at the weld of the steel structure are within the allowable stress intensity range determined by Goodman curve,which shows that the fatigue strength of the fuel tank weld can meet the strength requirements of locomotive operation.(3)At last,the static strength test of the car body structure after structural improvement is carried out to ensure that the structural strength and stiffness of the car body are reasonable on the premise of meeting the design requirements,so that the strength and stiffness of the car body of the centralized power internal combustion EMU have been improved very well.At present,this type of locomotive has completed the manufacture and static strength test of the whole vehicle,and is ready to carry out the application assessment. |
