On the modelling of normal wheel-rail contact for high-frequency vehicle–track dynamics analyses

ABSTRACT

A transient wheel–rail rolling contact (RC) model and a vehicle–track coupled dynamics (CD) model are separately developed for a Hertzian contact in elasticity to calculate normal wheel–rail interactions at high frequencies. Short-wave irregularities with a wavelength of 20 ~ 400 mm are considered for a speed of 50 ~ 500 km/h. Results of 180 cases show that contact forces predicted by the CD model are significantly different from those by the RC model, suggesting that ignored or greatly simplified structural and wheel-rail flexibilities, transient effects, finite contact patch, etc. in the CD approach, play important roles in high-frequency interactions. Using the RC predictions as reference, a modified non-linear Hertzian spring is developed to improve the accuracy of the CD model. Such a modification provides references for determination of contact spring and contact filter effect at high frequencies, even though not applicable in a direct way.

KEYWORDS:

• Wheel–rail interaction
• normal contact
• hertzian spring
• short-wave irregularities
• transient rolling contact
• multi-body dynamics
• vehicle–track coupled dynamics
• contact filter effect

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The present work is supported by the National Natural Science Foundation of China (52027807), the Science & Technology Research Program of Sichuan Province (2021YFH0006), and the Autonomous Research Project of State Key Lab of Traction Power (2019TPL-T17).