Preferable Stability Speed of Metro Vehicles Passing Steel Spring Floating Slab Tracks with Worn Wheels

Abstract

[Objective] To enhance metro passenger riding experience, the speed range at which the carbody exhibits optimal stability while passing through tracks laid with floating slabs is explored. [Method] Using simulation software, a dynamics model of metro vehicle-floating slab track-subgrade is established to analyze the carbody vibration conditions when standard and worn wheels pass through tracks with or without steel spring floating slabs. Comparative analysis is conducted on the changes in carbody vertical stability index in time and frequency domains under different speed conditions, both before and after the installation of floating slabs. Additionally, under the floating slab track system, the change law of time and frequency domains of parameters such as carbody vertical vibration acceleration is compared between the worn and standard wheels passing through the floating slab track system. [Result & Conclusion] The presence of floating slabs at different speeds increases train stability index, showing an average increase of 5.8% compared to scenarios without floating slabs. The lateral stability index has a reducing effect on stability index when the speed is below 60 km/h. In the floating slab system, the presence of worn wheels exacerbates carbody vertical vibration, particularly noticeable when trains are running at high-speed. The vertical acceleration frequencies during metro vehicle passing tracks concentrate in the low-frequency range of 0-10 Hz, while the lateral ones concentrate in the 0-30 Hz range. When metro vehicles pass through sections with floating slabs at the speed in 48-60 km/h range, the carbody vertical stability index with worn wheels is approximately 1.8, and the lateral one is around 1.1, both of which are relatively low, indicating less carbody vibration and lateral movement, thus better stability.

Keywords

• metro
• worn
• steel spring floating slab
• vibration