Structural Optimization Of Train Wheelset Based On Modal Analysis

Development of railway has been highly valued by the state.Railway has become an important symbol of China’s comprehensive national strength and the main development advantage of our country in international competition.With the continuous improvement of speed,more and more attention has been paid to the smooth running of train.As an important part of the train bogie,the wheel pair bears the important role of guidance and bearing during the train operation.The stability of wheelset directly affects the smooth running of train,so it is necessary to study the structural characteristics of wheelset and optimize its structural parameters.In order to effectively study the mechanical property of wheelset,this paper takes the wheel pair model of CRH380 train and its size to the actual size is 1:2 as the research object.The finite element model of wheelset model is constructed,and the finite element modal analysis is carried out according to finite element model.The finite element analysis is combined with the experimental modal analysis to modify the finite element model.On the basis of the model reliability,the structure size of wheelset is optimized.Firstly,the geometric 3D model is set up in SolidWorks based on the actual size of wheelset model,and the model is introduced into the ANSYS.According to the material properties and structural characteristics of wheelset,material parameters are set up and meshes are divided,so as to establish wheelset finite element model.Finally,finite element modal analysis is carried out for finite element models.The output response signal of the wheel is finally obtained.Secondly,the modal experiment system is set up to collect the test modal data of the wheelset.The excitation of impact hammer is used as the incoming signal of the system,and acceleration sensor is used to measure the acceleration signal of the response,and data collector is used to collect the experimental data.Based on the modal experiment system,the response of the wheelset are finally obtained.Thirdly,the signal is preprocessed and the modal parameters of the response signal are identified.First,the original signal is filtered according to the characteristics of the experimental data,and then the modal parameters are obtained by the Hilbert Huang transform(HHT).The transformation is divided into two parts: empirical mode decomposition(EMD)and Hilbert transform.The phenomenon of decomposition is avoided by adding bandpass filters.The results show that the improved EMD decomposition can effectively decompose the response signal and obtain the actual modal parameters of the wheelset.By comparing the results of the calculation and the test analysis,the finite element model of the wheelset is modified to improve the reliability of the wheel set model.The results show that the error between experiment and simulation can be controlled within 5% after the correction of the model,which verifies the reliability of the model,and provides a precondition for the structural optimization.Finally,the size parameters are optimized on the basis of the reliable finite element model of wheelset.The overall length,diameter and width of wheel are optimized in consideration of the factors such as quality,deformation and stress of the wheel.The results show that the quality of wheelset was reduced by 11.495%,the total deformation was reduced by 16.6%,and the maximum equivalent stress was also reduced by 4.87% after the size optimization.Thus,the manufacturing cost of wheelset is reduced,the stability of operation is improved and the degree of fatigue damage is reduced.