Twin-disk 시험기를 활용한 열차 속도에 따른 휠과 레일에서 발생하는 진동 특성 연구

초록

Wheel-rail interaction-induced vibrations are inherent to railway vehicles and significantly affect phenomena such as adhesion coefficients, rolling noise, and wear. Although a previous study investigated these vibrations using a twin-disk wheel-rail contact simulator under a single speed condition, the effect of train speed on wheel-rail contact vibration remained unclear. This study extended the aforementioned previous study by conducting experiments at three rotational speeds: 1200r/min, 1800r/min, and 2400r/min, corresponding to approximately 45km/h, 68km/h, and 90km/h, respectively. The experiments involved high-carbon steel specimens with flat-tread wheels and head-profiled rails under dry surface conditions, and vibration was measured during the acceleration, slip, and deceleration phases at each speed. Time-domain moving RMS envelopes and Welch-based power spectral densities were used to characterize the vibration. In the acceleration, rolling/sliding-contact, and deceleration zones, the RMS levels of both wheel and rail vibrations increased monotonically with rotational speed. The peak amplitude in the 1kHz~2kHz band also increased markedly with speed for both wheel and rail vibrations across these zones. The peak frequency remained nearly constant (approximately 1290Hz~1310Hz) for rail vibration; however, it exhibited larger variability for wheel vibration, particularly in the pure sliding-contact and deceleration zones. In the pure sliding-contact zone, the RMS levels exhibited no monotonic trend, possibly owing to transient motor-control fluctuations and specimen wear during sequential testing. Further verification tests are required to clarify this behavior. These findings extend the understanding of wheel-rail contact vibration established in a previous study by incorporating train speed as an additional influencing factor.

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