Research On The Mechanism And Control Method Of Running Wheel Partial Wear Of Straddle-type Monorail Vehicle

As a new type of urban rail transit system,straddle-type monorail transportation is being popularized and applied in our country.The bogie structure of straddle type monorail vehicle is unique.It has the characteristics of small running line curvature and many curves.The tyre of the running wheel of the vehicle is seriously worn out and needs to be replaced frequently.The maintenance costs is great.Therefore,it is urgent to carry out the research on the mechanism and control method of the running wheel partial wear.This article relies on the National Natural Science Fund Project "straddle type monorail wheel wheel tire partial grinding mechanism and control method research"(item number:51475062),in order to reduce the partial wear of straddle wheel of straddle monorail vehicle,the equivalent test system of monorail vehicle is established,the model of rail relation model and the spatial coupling dynamics model of monorail vehicle are established,the mechanical reasons of partial wear of the running wheel of single track vehicle are analyzed,and the influence and regularity of vehicle parameters on the partial wear of running wheel tires are studied,and the mechanism of eccentric wear of the running wheel are revealed.The partial wear coefficient model and the prediction model of the running wheel are constructed to form a perfect evaluation system of the partial wear of the running wheel,coordinated matching relationship of vehicle parameters is studied,and control method for partial wear of running wheel of single track vehicle is developed.The main research contents and achievements are as follows:(1)The moving mechanism of straddle monorail vehicle is analyzed,the equivalent theory of wheel rail interaction is studied,and the mutual dynamic interaction test system of monorail vehicle track beam is constructed.The simulation test system of"vehicle-rail beam" was established by multi-body dynamics and finite element analysis.A physical test and simulation test in one,the actual situation combined with each other to complement the monorail vehicle runner partial grinding research test system is built,which provides an important research basis and means for the subsequent analysis.testing and verification of the monolithic vehicle runner tire partial grinding mechanism and control method.(2)The spatial topological structure of straddle monorail vehicle is analyzed.Based on the theory of multi-body dynamics,the wheel/rail multi contact relationship model of running wheel,guide wheel,stabilizing wheel and rail beam is established in the space domain,the running wheel tire model is studied,and the spatial coupled dynamic model of straddle type monorail "vehicle-tire-brack Beam" is constructed.Based on the wheel rail relation model and the dynamic model,the force forms of the running wheel.the guide wheel and the stabilizing wheel are studied,and the mechanical boundaries of the wheel tire wear mechanism and the control method are provided.(3)The mechanical reason of wheel tire partial wear is studied,and the lateral dynamics model of monorail vehicle is established to reveal the wear mechanism of wheel tire.When the monorail vehicle passes through the curve,The coupling effect of the vertical force of the running wheel,the guide wheel and the stablity wheel in the transverse direction causes the inclination and slipe state of the running wheel,so that the longitudinal shear force and the lateral shear force and the corresponding slip amount acting on the running tread are unevenly distributed along the axial direction,resulting in partial wear of the running wheel.The magnitude of the shear force distribution gradient in the wheel rail contact zone is affected by the vertical force of the guide wheel and the stabilizing wheel,the vertical force of the running wheel,the side force of the side wheel of the running wheel and so on,thereby affecting the degree of partial wear of the running wheel.Based on the combination of multi-body dynamics and finite element method,the wheel tire wear model of running wheel is established from two aspects of macro and micro,the evaluation index of running wheel partial wear is put forward,and the influence of structural parameters and dynamic parameters of the monorail vehicle on the partial wear of the running wheel is revealed.Based on the global sensitivity analysis,the sensitivity analysis of key influencing factors is carried out by using Monte Carlo method,and the main factors affecting the partial wear of the running wheel are analyzed.(4)According to the factor analysis theory,the partial wear factor model of the running wheel of the monorail vehicle is established,and the factor score formula is deduced.The factor score method of the partial wear of the running wheel under the single monorail vehicle design scheme is put forward,a comprehensive evaluation index of running wheel partial wear is formed.Based on the theory of support vector machines(SVM)nonlinear regression algorithm,the prediction model of running wheel wear factor is established.It is found that the main factors that affect the partial wear of the running wheel are the structural parameters of the monorail vehicle,the longitudinal and lateral dynamic parameters of the running wheel train,the vertical stiffness factor of the running wheel and the vertical stiffness factor of the air spring.The prediction model can accurately and accurately be used to predict the partial wear state of the monorail wheel.(5)Take the partial wear control of the running wheel as the optimization objective.Based on the improved genetic algorithm,The optimization model based on the structural parameters and dynamics parameters of the monorail vehicle as the set of variables and the wear factor of the running wheel is established.From the angle of vehicle structure parameters and dynamic parameters matching,a method to control the partial wear of the wheel of monorail vehicle is put forward.The results show that the three partial wear evaluation indexes of the traveling wheel eccentric wear factor,the running wheel friction work and the friction crest value are obviously decreased,and the partial wear performance of the running wheel is improved obviously.