| With the gradual enhancement of Chinese comprehensive strength and the sustained and rapid development of the economy,the role of transportation led by Electric Multiple Unit(EMU)in social life has become increasingly prominent.In order to improve the happiness index of people’s daily transportation,the number of trip and mileage for the trains gradually increased,which made the safety of bullet trains require more attention.As the skeleton of the EMU,the potential safety hazards is caused if its safety performance does not meet the requirements.The occurrence of this phenomenon bounds to affect the safety of people’s lives and property.At the same time,in order to reduce the cost of raw materials and later manual maintenance,on the basis of ensuring safety performance,enterprises should appropriately adopt lightweight design,which is more conducive to improving the cost performance of products,and can ensure that Chinese EMU industry continues to maintain a leading position in the international sales market.This thesis refers to the UIC615-4 standard and analyzes the structural performance of a bogie of an EMU by the finite element method.First,the 3D modeling software SOLIDWORKS was used to draw and assemble the components of the bogie frame,and the error was controlled within 0.01 mm.The 3D model was then imported into Hyper Mesh to draw the finite element mesh,apply 1D elements,and assign material properties.After that,the abnormal working conditions,main operating conditions,and special working conditions were set,constraints and loads were applied,and ANSYS was imported for static strength simulation calculation.Through the stress cloud map,it can be concluded that the structure meets the static strength requirements and there is still room for optimization compared with the allowable stress.Then,the Lanczos method is used to analyze the 10th-order free mode of the architecture,and the number of frequencies of the first order is greater than the natural frequency of the architecture,so the resonance phenomenon of the architecture will not occur.Because the location where the stress was weak,the fatigue assessment point is selected and the Goodman-Smith fatigue limit diagram is drawed according to the material properties.The selected risk assessment points are all located in the fatigue limit map,and the fatigue strength meets the design requirements;After that,it is necessary to define the more dangerous weld and import the Weld-Fatigue software,the fatigue life is alculated based on the main S-N curve method,and a detailed analysis of the weld with the main force is conducted,and the fatigue life meets the design requirements;Using sensitivity analysis,the optimized plates were determined,and the working conditions with the greatest stress in the static strength analysis were selected to optimize the size of the plate thickness reduction,with a total weight reduction of 10.1%.After conducting static strength,modal,and fatigue analysis on the optimized plate thickness of the bogie,it was found that after lightweight design,the safety performance of the framework still meets the requirements.Through the above research and analysis,it can provide theoretical support for this bogie frame to meet the structural performance requirements under the requirements of the given working conditions,and provide a reference basis for the lightweight design of the frame. |
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