The vibration behavior of railway track at high frequencies under multiplepreloads and wheel interactions

The track foundation is preloaded by multiple wheel loads due to the train weight and, as the pad and ballast are nonlinear, their stiffness depends u pon the preload in them. Due to the influence of these resilient components of the track, the track vibration is affected by the wheel loads. It is al so affected by the wheel/rail interactions. In this article the preloads in the pad and ballast are calculated by considering the nonlinear properties of the track foundation, and thus the preloaded pad and ballast stiffnesse s are determined. The vibration properties are explored for the track under multiple wheel loads and multiple wheel/rail interactions by comparing the results from different track models with and without these effects. It is found that the point receptance of the track is reduced and the vibration d ecay rate is enhanced at low frequencies due to the wheel loads. The effect s of the wheel/rail interactions are most significant for frequencies 400-2 000 Hz. Because of the wheel/rail interactions, the point receptance fluctu ates and the vibration decay is enhanced in the regions around the wheels. (C) 2000 Acoustical Society of America. [S0001-4966(00)02409-7].