A study on the dynamic behavior of the Korean next-generation high-speed train

Abstract

This study describes the dynamic behavior of the HEMU-430X, the Korean next-generation high-speed train. The HEMU-430X was initially analyzed using VAMPIRE, a computer program that is used to examine the dynamics of railway vehicles, based on which it was expected to sway strongly at its tail end. This hunting motion was expected to disappear when the position of the yaw damper was changed. The dynamic behavior of the HEMU-430X was assessed in an on-track test performed using the protocols in the EN14363 standard and measuring the carbody, bogie and axle accelerations; the HEMU-430X was found to satisfy the safety criterion. The hunting motion appeared at speeds of 150, 350 and 387 km/h, and countermeasures such as changing the position of the yaw damper, installing carbody dampers, and increasing the damping coefficient of the yaw damper installed on the motor car containing the driver's cab were taken in order to reduce the vibrations. Ultimately, the highest test speed achieved was 421.4 km/h. Subsequently, it was found that the critical speed tended to decrease with mileage. This was attributed to excessive lateral damping and a revised design was proposed to solve this problem.

Investigation of low damped carbody oscillation for Korean high-speed EMU experimental train

“…The last 16 wheels were recently reprofiled. As in the previous study, 1 the combined mode of lateral and roll directional motion of the carbody was observed, and the hunting frequency was also similar. However, it was observed in the Tc and M1 cars regardless of driving direction, while the previous hunting occurred mainly in the Mc car when the Mc was the rear-end car.…”

“…In the test period, the HEMU-430X had undergone a hunting problem, but it was effectively reduced due to several measures such as changing the installation place of yaw damper, implementing intercar dampers, reducing lateral damping effects. 1 The reliability test was also finished successfully as a cumulative mileage of 100,000 km was attained in 2015. Since 2016, it has been served as a test bed for the R&D of railway vehicle components.…”

“…Recently, the HEMU-430X experienced similar but slightly different hunting problem after some wheels were changed to XP55. The initial wheel profile was S1002 but the 16 wheels of two cars were reprofiled in the latter half of the test period, 1 and other 16 wheels were changed in the late 2015. The last 16 wheels were recently reprofiled.…”

EMD-Based Methodology for the Identification of a High-Speed Train Running in a Gear Operating State

“…The full-scale tests with rolling stock in an open track are extremely unusual, especially if we talk about in-service trains. In fact, Jeon et al [ 24 ] recorded the vibration data from the axle boxes of a high-speed train running at very high speeds. However, these measurements were picked up from a prototype train in development under trial conditions.…”

Theoretical study on the effect of the anti-yaw damper for rail vehicles

“…Jeon et al. 6 studied the dynamic behavior of the Korean next-generation high-speed train through the VAMPIRE software and field measurements. They found that the swaying phenomenon of the tail car body was effectively avoided by adjusting the damping coefficient and installation position of yaw dampers.…”