| Local track irregularity is easy to appear in the line of some special places. For example, track local nodical irregularity is seen at the bridge pier, small span bridges easy to present the flat-type local irregularity, the local track irregularity will further generate deteriorate development are the locomotives and track interaction.The local irregularity was simulated by the MATLAB software, inputted to the locomotive model as external excitation. Established the dynamics model of locomotive by means of the multi-body dynamics simulation software SIMPACK. The locomotive wheel-rail dynamics index was based on the locomotive vertical force theory. Analyzed the different wave number of local irregularities, different local irregularity parameters and the deterioration of local irregularity on locomotive wheel-rail dynamic performances. The locomotive wheel-rail system have stick-slip excitation will cause the wheel rail adhesion coefficient cyclical changes and drive system has strong vibration, will lead to the deterioration of the safety and comfort performance. And the wheel longitudinal vibration will cause locomotive complex dynamic behavior. The main work is as follows:(1) According to MATLAB software with numerical simulation method to transfer the spatial frequency domain random irregularity of US 5 track spectrum to time domain track irregularity. The simulated track irregularity’ was inputted to the simulation locomotive model as the external excitation. Verified and analyzed the established locomotive dynamic model.(2) The simulated track irregularity was inputted to the simulation locomotive model as the external excitation. Analyzed the influences of track local nodical irregularity and different continuous wave number irregularity on the locomotive safety and comfort. Discussed the effects of the flat-type local irregularity amplitude A, the coefficient K associated with irregularity wavelength and the flat top length L on the wheel-rail dynamic performance. The results show that, with the certain nodical irregularity amplitude and wave length the more nodical irregularity wave number, the more influences on locomotive safety and comfort, that are all more than the single random irregularity. The increase of the flat-type irregularity A and the irregularity wave length coefficient K has different extent influence to the maximum locomotive wheel-rail vertical force and the wheel load reduction rate. Otherwise, the flat top length L almost has no effect on the maximum of wheel-rail vertical force and the wheel load reduction rate.(3) After the line opening, the main reasons of the local track irregularity occurrence, development and worsening are the locomotives and track interaction. Local track irregularity will further generate new development, various initial irregularity will gradually increase and deteriorate. The local development track deterioration will further affect the dynamic action between wheel and rail. The simulation results show that when harmonic local irregularity and nodical type local irregularity bump deterioration occurs, even if small amplitude deteriorates will cause serious deterioration of wheel-rail dynamic response and strong wheel-rail shock and vibration. The wheel-rail dynamic forces increases with the speed increasing.(4) When the wheel-rail tangential force was saturated the wheel in the big sliding state and wheel-track adhesion coefficient was reduced with the increases of creep. The characteristic curves of wheel-rail negative slope adhesion will cause part of the transmission system (e.g.:motor, rotor, small gear), wheel set and frame increase of acceleration in some direction. On the components other direction, the vibration response has no significant change with no stick-slip vibration. |
PDF Full Text Request