Research on Bench Test Method for Bogie Frame Based on Measured Line Load

Taking the bogie frame of the high-speed train as the research object, the time history curve of the axle box spring load and the primary shock absorber load of the bogie is obtained through the line test, and the influence law and the load difference of the train entering and leaving the station, different speed levels, and load frequency on the spring load and the primary shock absorber load is analyzed. The load stress transfer relationship between the spring load, the primary shock absorber load and the fatigue danger point of the end structure of the frame is obtained by using quasi-static loading bench test. The stress response curve is obtained by combining the actual line load calculation, and then the fatigue damage value of the frame under the spring load, the primary shock absorber load and the coupling of the two loads is obtained. According to the fatigue damage consistency theory, calculate the spring equivalent load and the primary shock absorber equivalent load of the frame under the vehicle design mileage, establish the fatigue damage calculation formula based on the equivalent load, determine the phase relationship between the spring equivalent load and the primary shock absorber equivalent load, and finally form the frame bench test method based on the measured line load. The research shows that the axle box spring load fluctuates greatly when the train entering and leaving the station, the maximum fluctuation range is 17.48 kN, and the primary shock absorber load is not sensitive to the low-frequency displacement response; With the increase of train operation speed, the axle box spring load and primary shock absorber load show an increasing trend, and the load frequency is mainly distributed in the range of 0-60 Hz; At the same time, the phase difference between the two loads decreases with the increase of load frequency in this frequency band, which is related to the dynamic characteristics of the shock absorber. It is calculated that the fatigue damage of the frame end under spring load, primary shock absorber load and coupling load is 0.014, 0.011 and 0.061respectively. Based on the fatigue damage consistency criterion, the spring equivalent load and primary shock absorber equivalent load are 7.54 kN and 4.51 kN respectively; When the phase of the primary shock absorber equivalent load is about 60 ° ahead of the spring equivalent load, the fatigue damage of the frame is the same as the measured fatigue damage of the line. Then the ph