Study On Vehicle Dynamic Performance On Rail Grinding

With the increase of railway operation mileage,train speed and freight volume,long-term contact with high-strength wheels and rails will cause rail damage.Rail damage will not only greatly reduce the rail life,but also worsen the wheel rail relationship,increase the noise of train operation,and greatly threaten the safety and stability of train operation.Rail grinding is the most economical and effective rail maintenance measure at present.Rail grinding can repair Rail profile,improve wheel-rail contact relationship,remove rail damage,reduce wheel-rail vibration,improve track stability and reduce train running noise.With the development of railway toward high speed and heavy load,the force between vehicle and track will be more and more big,which will aggravate the contact fatigue and wear between wheel and rail.The deterioration of running conditions between wheel and rail will lead to incalculable loss of train derailment,which will cause incalculable losses.At the same time,the increase of wheel-rail force will shorten the service life of wheels and rails.Wheel-rail interaction force can reflect the safety and stability of train operation.In order to analyze the operation conditions and life of rail and wheel,it is necessary to test wheel-rail interaction force.Because of the obvious randomness of wheel-rail interaction force caused by external factors,the numerical value of wheel-rail interaction force is obtained by experimental method.This thesis mainly studies the influence of rail grinding on the dynamic performance of railway vehicle,and analyses the influence of rail grinding on wheel-rail interaction force and vehicle running safety.Accurate acquisition of wheel-rail interaction force is an important research topic.In this paper,experimental method is used to obtain wheel-rail interaction force.In order to accurately obtain the magnitude of wheel-rail force,this thesis designs a wheel-rail force test system,which is mainly divided into two parts: calibration system and test system,in which the calibration system includes calibration device and pressure system.In this thesis,a calibration device for wheel-rail force is designed,and the strength analysis and feasibility verification are carried out by using ANSYS.The wheel-rail force pressurization system is mainly composed of hydraulic jack,pressure sensor and A/D conversion card.The data acquisition system of the pressure system is compiled by using LABVIEW.The feasibility of the testing system is verified in laboratory and field.In order to analyze the influence of rail grinding on the dynamic performance of railway vehicle,the dynamic changes before and after rail grinding are studied experimentally.This thesis test the wheel-rail force of passenger trains,freight trains,freight locomotives,passenger locomotives,freight cars and passenger cars under normal conditions,grinding conditions and grinding + sprinkler conditions respectively.The experimental results show that rail grinding can reduce wheel-rail vertical force,wheel-rail lateral force,derailment coefficient and wheel load reduction rate.Rail grinding after water spraying can reduce wheel-rail vertical force,wheel-rail lateral force,derailment coefficient and wheel load reduction rate better than rail grinding.Rail grinding can reduce vertical vibration acceleration of outer rail,and increase vertical vibration acceleration of inner rail.Rail grinding can not reduce lateral vibration acceleration of internal and external rails.The simulation model of vehicle dynamics meeting the experimental requirements is established by using SIMPACK.According to the field data of rail grinding,the influence of rail grinding on the dynamic performance of vehicle on straight line and curve is analyzed.The simulation results show that rail grinding can reduce wheel-rail vertical force,wheel-rail lateral force,wheel-axle lateral force,wheel load reduction rate and derailment coefficient.Rail grinding can improve the lateral stability of vehicles,but has little effect on the vertical stability of vehicles.