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Preload on draft gear in freight trains

journal contribution
posted on 05.02.2019, 00:00 by Qing Wu, Colin Cole, Maksym Spiryagin, W Ma
Adjusting draft gear preloads requires minimum or no structural changes to the existing coupler systems. Better or optimal preloads are more promising to be implemented than modifying other parameters such as wedge angles and spring stiffness. This paper presents a method to model draft gear preloads and investigates the numerical step-size requirements for the simulations of draft gear preloads. The implications of preloads on the draft gear impact performance, longitudinal train dynamics performance and coupler fatigue damage were also investigated. The results show that step sizes of less than 2.5 and 0.2 ms (with the fourth Runge–Kutta solver) are recommended to simulate preloads during the simulations of longitudinal train dynamics and wagon impacts, respectively. Wagon impact simulations indicate that the increase of draft gear preloads can noticeably decrease the maximum draft gear deflection during wagon impacts. Longitudinal train dynamics simulations for a distributed power train with 214 vehicles on a 320 km long track were conducted. The longitudinal train dynamics simulations indicate that, when the preload is increased from 0 to 100 kN, the difference of maximum vehicle accelerations is insignificant. When the draft gear preload is further increased to 200 or 300 kN, maximum vehicle accelerations are evidently increased. Draft gear preloads do not noticeably influence the maximum tensile coupler forces. However, preloads have evident implications for maximum compressive coupler forces, especially for the second half of the train. Coupler fatigue damage calculations show that the sum of coupler fatigue damage evidently decreases with the increase of draft gear preload. The damage for the zero preload case is 8.7 times than that of the 300 kN preload case. © 2017, IMechE 2017.

Funding

Category 3 - Industry and Other Research Income

History

Volume

232

Issue

6

Start Page

1615

End Page

1624

Number of Pages

10

eISSN

2041-3017

ISSN

0954-4097

Publisher

Sage Publications, UK

Peer Reviewed

Yes

Open Access

No

Acceptance Date

01/10/2017

Author Research Institute

Centre for Railway Engineering

Era Eligible

Yes

Journal

Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit

Exports