Tests for coupled vibration of a train-bridge system on Changsha low-medium speed maglev line

In order to study effects of different bridge structures on coupled vibration of a low-medium speed maglev train-bridge system, field tests were conducted for a maglev train running on two typical bridges of Changsha low-medium speed maglev commercial operation line including a 25 m simply-supported girder bridge and a (25+35+25) m continuous one. Dynamic responses of vehicles and these two bridges were measured. Firstly, fundamental frequency characteristics of these two bridges were analyzed and compared with simulated ones. Then, dynamic characteristics and vibration acceleration spectra of the train and two bridges were analyzed. The results showed that the simulated fundamental frequencies of the two bridges agree well with the measured ones; under the action of the maglev train, the two bridges' vertical vibration acceleration peaks are concentrated in the frequency range of 0-20 Hz, while their lateral vibration acceleration peaks are distributed in the frequency range of 20-80 Hz; vibration acceleration amplitudes of the simply-supported girder bridge are totally larger than those of the continuous one; vibration spectral peak distributions of car bodies and suspension side frames when the train passing through the simply-supported bridge coincide with those when the train passing through the continuous one, vibration amplitudes when the train passing through the former are larger than those when it passing through the latter; vertical and lateral vibration accelerations of suspension side frames are much larger than those of car bodies, so air springs have good vibration isolation effect; the results can provide a reference for designing magnetic suspension viaducts and formulating corresponding norms and standards. © 2019, Editorial Office of Journal of Vibration and Shock. All right reserved.