Research On Design Scheme Of In-position Modal Test Bench For Frame

With the technological progress of rail transit industry,the research and development of test equipment has been paid more and more attention.In order to explore the in-position mode of bogie frame,this paper designs the in-position mode test-bed of frame.The thesis is carried out from two aspects: the structure scheme and the simulation test.The main work contents and conclusions are as follows:(1)Based on the performance parameters of subway train bogie and the first 8order modal frequencies of the frame,the technical specifications of the test bed were determined,including the maximum operating speed of 100 km/h,the maximum excitation frequency of 192 Hz,and the maximum vertical load of 250 KN.According to the reason of frame vibration and the influence of polygon wheel on dynamic performance,the excitation mode of polygon track wheel on test bed was determined.(2)Based on the performance parameters of subway train bogie and the first 8order modal frequencies of the frame,the technical specifications of the test bed were determined,including the maximum operating speed of 100km/h,the maximum excitation frequency of 192 Hz,and the maximum vertical load of 250 KN.According to the reason of frame vibration and the influence of polygon wheel on dynamic performance,the excitation mode of polygon track wheel on test bed was determined.(3)For MTS and dummy car body loading schemes,dynamic simulation is carried out by using dynamic model.The maximum difference of average stress is 1 Mpa,and the maximum difference rate is 2.43%.Considering the convenience of engineering operation,the MTS loading mode of the test bed is determined.(4)Various indexes of polygon track wheel under different amplitudes were simulated and compared with the existing control standards.Under the dual conditions that no wheelset jump occurred within 0-90 km /h and 120 KN warning value was covered,the amplitude of the 13 th order polygon of track wheel was determined to be0.03 mm.The actual curvature interval of track wheel profile is calculated as to ensure the satiety of polygon.(5)Based on the MTS loading and the polygon parameters of the track wheel,the frame on the test bed was simulated and compared with its in-position mode.The results show that the sixth mode of the frame can be excited by the same phase of the 1234 track wheel,and the modal frequency is 83 Hz.The antiphase of track wheels 12 and 34 can excite the 4th and 7th modes of the frame,corresponding to the mode frequencies of75 Hz and 112 Hz.The anti-phase of track wheels 13 and 24 can excite the 1st,6th and8 th modes of the frame,corresponding to the mode frequencies of 42.1 Hz,84.8 Hz and140 Hz.The excitation frequency and phase both affect the modal response of the frame,and the same mode of motion can excite the same mode of vibration.The feasibility of the design scheme of the test bed is verified and the guidance for the test is provided.