High-speed maglev train-track beam coupled system track irregularity sensitive wavelengths

Track irregularity is one of main excitation sources to induce coupled vibration of a vehicle-bridge system. Exploring irregularity sensitive wavelengths of system coupled vibration has important reference value for line management. Here, firstly, a spatial model of a high-speed maglev train-track beam coupled system was established. Maglev train was simulated as a multi-body dynamic model with 537-DOF, and track beam was simulated as a spatial finite element model. The two were coupled through magnet-rail relation based on proportional-differentiation (PD) control theory. Secondly, taking Shanghai high-speed maglev train as the study background, choosing a 5-car train passing through a 20-span simply supported beam bridge as the calculation condition, the correctness of the model was verified by comparing the calculation results with the measured results. Finally, considering track harmonic irregularity excitations, effects of different combinations of track irregularities in different directions, different amplitudes of track irregularities, and different vehicle speeds on sensitive wavelengths of train and bridge dynamic responses and the stability of train operation were explored. The results showed that the coupling between lateral and vertical vibrations of maglev vehicle-bridge system is very weak; at a design speed of 430 km/h, sensitive wavelengths of vertical, roll and pitch accelerations of vehicle body are 140-180 m, 60-100 m, and 120-160 m, respectively; sensitive wavelengths of lateral and yaw accelerations of vehicle body are larger than 200 m; when wavelengths are 80 m, 105 m, 115 m, 140 m and 160 m, respectively, they can cause resonances in roll, yaw, lateral, pitch and vertical directions of vehicle body, respectively; response amplitudes of vehicle body and main beam are basically linearly related to amplitude of track irregularity; when amplitude of track irregularity is 1 mm, peak roll acceleration of vehicle body does not change significantly under conditions of calculation vehicle speeds of 200, 250, 300, 350, 390 and 430 km/h, while peak accelerations of the other 4-DOF decrease with increase in vehicle speed; vertical acceleration amplitude of main beam increases linearly with increase in vehicle speed; observing lateral and vertical Sperling indexes of vehicle body, they are both less than 2. 5, so the operation stability of maglev train is good. © 2024 Chinese Vibration Engineering Society. All rights reserved.