Structural Analysis And Optimization Methods Research Of High Speed Train Body

High speed and modernization of the high speed train make the structure of the body bear more complex load,it may lead to the decrease of the structural strength,stiffness and ride comfort.The lightweight research of the car body structure can lower the cost of the materials,reduce traction power,improve the running speed of the train and increased the service life of the high speed trains and lines.In the operation of the vehicle,the components bear the load of different directions and sizes,in order to achieve the lightweight structure of the body,it is necessary to ensure the strength and stiffness of the body structure meet the standard requirements.Firstly,by comparing and analyzing the usual standard of static strength of body structure,the finite element calculation of vehicle structure is determined by the suitable load condition,and 5 typical cases are selected to analyze the static strength of the structure.The maximum stress of the body under different loads is 208.1 MPa,which is less than the allowable stress of the body material,and indicates that the body’s static strength meets the standard requirements.The vertical bending load and torsional load are analyzed,and the results show that the equivalent bending stiffness and torsional stiffness of the car body are 2.8007 ×109 N·m2 and 10.837 ×108N·m2/rad,respectively.It is greater than the reference value of the standard,which indicates that the stiffness of the car body meets the requirements.Secondly,the computational modal and experimental modal analysis of the proportional carbody under different boundary conditions are carried out,three different spring constraint experimental modal of the structure vertical frequency and the free modal frequency error value are 2.545%,2.961%and 4.812%,respectively,to verify the accuracy of the finite element modeling.The optimization of four different optimization platforms and the optimization algorithm is studied.The comparative analysis shows that the feasible direction method in Opti Struct has the advantages of less number of iterations,short computation time and better optimization effect.Finally,the optimization model of car body structure is established in OptiStruct,and the sensitivity analysis of the vehicle body is analyzed to determine the suitable design variable.Using the continuous design variables and discrete design variables to optimize the structure of the vehicle,the quality of the vehicle is reduced by 1.97453 t and 1.99174 t respectively by the continuous design variables and the discrete design variables.respectively,the reduction is 24.094%and 24.679%respectively.To perform the performance check on the optimized body structure,the maximum stress is 179.7 MPa(continuous)and 177.5 MPa(discrete),which is less than the allowable stress value of the material.The equivalent bending stiffness and torsional stiffness is 2.1656×109N·m2 and 10.748 ×108 N ·m2/rad,respectively,which is greater than the standard reference values.It is not less than the optimized initial value of the optimized vehicle structure,indicating that the optimized body structure meets the performance requirement.In this paper,the study shows that the appropriate optimization platform and algorithm can effectively realize the lightweight design of lage and complex structures,at the same time,the optimized structure of the car body can meet the requirements of strength,stiffness and modal frequency.