Urban rapid transits are one of the most popular transportation methods these days. They are equipped with large-capacity air compressors because they use pneumatic pressure to supply power for braking, door opening and closing. Passengers tend to complain about vibration and noise generated during the operation of the air compressor. To address such issues, the excitation force generated in an air compressor mounted on a railway car was indirectly measured in this study. In order to accurately predict the excitation force transmitted to the mount rubber, the impedance matrix method technique was applied, which uses acceleration and the inverse of transfer functions. The proper locations of the measuring acceleration were also investigated. The calculated results of the transmitting force were then compared with the directly measured values.
air compressor, frequency response function, impedance matrix method, transfer path analysis, vibration
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