Fatigue Test Load Spectrum Of Bogie Frame Based On Measured Load

With the increase of the speed of high-speed trains and the increase of operation mileage,it is more and more important to evaluate the fatigue strength of vehicle structural components to ensure safety.The bogie frame is the key bearing part of the high-speed trains,and it is an important part of the vehicle walking device.It directly affects the safety and stability of the vehicle operation.So it is necessary to evaluate the fatigue strength of the vehicle to ensure the safety of the operation.This dissertation focuses on the load of the standard high-speed trains'bogie frame when it is actually in operation and uses the measured data to compile the load spectrum of the bench test of the simulated line measured load,which provides a reference for the test and improvement of the bogie frame.Clear bogie frame in the actual operation of loading is the basis of fatigue strength evaluation,and the bench test of the simulated line measured load is an effective way for fatigue strength analysis.It can not only accurately reproduce the load condition of the frame in the actual line running,but also reduce the test time and economize test cost.In this paper,taking the the standard high-speed trains as the research object combined with the load spectrum research which is an important basis for the evaluation of structural reliability.The load analysis,calibration test,line load and dynamic stress test,load spectrum compilation and damage calibration are carried out on the bogie frame.And compile the load spectrum of the bench test of the simulated line measured load.The main research work is as follows:(1)The types of load bearing load of bogie frame are classified and the location of dynamic stress measurement point and load identification point are determined.Laboratory calibration test is carried out to make dynamometer frame and the transfer relationship between load and various measuring points of frame is found to obtain the load transfer coefficient.It provides support for load identification,measurement and compilation of load spectrum consistent with damage consistency.(2)Line test of bogie frame is carried out to test all load and dynamic stress changes of bogie.The load in the circuit test is identified by using the dynamometer frame and the key parts of the bogie.The collected data were processed and analyzed to work out the frame load spectrum of the actual operation of the line,and the calibration coefficient was obtained by calibrating the damage consistency.And the consistency of the damage is calibrated to obtain a calibration coefficient.(3)The method of reducing the load time history is studied.According to the IIW standard,the fatigue cut-off limit is determined.The stress basis is found,and the synchronization between the stress time history and the load time history is reduced.The reduced load spectrum is calculated and the damage is calculated.The accuracy of the reduction is verified by comparing with the pre-reduced load damage.The research contents of this paper provide a train of thought for establishing load spectrum that can reflect the actual situation of our country and the loading condition of bogie frame.It provides load basis for the formulation of the structural strength design standard and the reliability test evaluation standard of the high-speed trains,which is in accordance with the conditions of our country,and to evaluate the use of the key parts accurately.The data base is provided for the study of the safety and reliability of the high-speed trains on the safety and reliability of the line.