Research On Physical Parameter Identification Of High Speed Train Body And ODS Expansion Of Vehicle Body

With the extensive application of the lightweight body on the high-speed train,the elastic vibration problem of the vehicle body has been widely concerned,which not only affects the comfort index,but also has a serious influence on the structure of the vehicle body.By studying the relationship between the inherent properties of the vehicle body and the dynamic response,the target mode of the vibration control can be accurately found,thus providing reliable improvement and optimization of the vehicle body structure.Therefore,the inherent parameters and vibration response of the car body have become the premise for studying the vibration characteristics of the vehicle.At present,although the theoretical research on parameter identification of vibration systems has been relatively perfect,the practical application of large structures such as rail car bodies has rarely been studied.Meanwhile,due to the limited actual conditions,the vibration response information obtained by the test is incomplete,which affects the accuracy of the dynamic analysis of the vehicle body.Therefore,in view of the above problems,this paper combines theoretical analysis and simulation verification to determine the method applicable to the physical parameter identification of the vehicle body,and identify the vehicle body parameters under the test conditions,then analyze the influence of the vehicle body mode on the vibration characteristics,finally the incomplete response information is expanded to obtain relatively complete information.The main research contents are as follows:Firstly,based on the vibration system parameter identification theory,the theoretical derivation and principle of the modal mode weighted orthogonality method,inverse eigenvalue method and error vector method are respectively explained,and the advantages,disadvantages and practicability of the three methods are compared.It is determined that the modal mode weighted orthogonality method is more suitable for the physical parameter identification of the rail car body structure.Then obtain the physical mass matrix and physical stiffness matrix of vehicle body.Secondly,the calculation method of the modal contribution of the complete modal model of the vehicle body is studied.According to the actual vibration result of a moving car body,the contribution of each mode to the vibration is calculated,and the vibration characteristics and the modal contribution of the vehicle are obtained.Then verify the correctness of the method of measuring the modal contribution used in this paper.Finally,based on the structural characteristics of the car body and the principle of curve and surface fitting,the finite-point information is used to fit the displacement response signal and the mode shape of the car body to respectively obtain the surface equations of the first and second side walls,the roof and the bottom of the car body under the first-order diamond,first-order vertical bend,first-order torsion,first-order transverse bend and first-order respiratory mode.Achieve the extension of incomplete information of vehicle body's ODS.