Comparison of calculation methods for wheel–switch rail normal and tangential contact

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2019

Self Cite

This paper aims at assessing several fast non-Hertzian methods, coupled with two wear models, based on the wheel–rail rolling contact and wear prediction. Four contact models, namely Kik-Piotrowski's method, Linder's method, Ayasse-Chollet's STRIPES algorithm and Sichani's ANALYN algorithm are employed for comparing the normal contact. For their tangential modelling, two tangential algorithms, i.e. FASTSIM and FaStrip, are used. Two commonly used wear models, namely the Archard (extended at the KTH Royal Institute of Technology) and USFD (developed by the University of Sheffield based on T-gamma approach), are further utilized for wear distribution computation. All results predicted by the fast non-Hertzian methods are evaluated against the results of Kalker's CONTACT code using penetration as the input. Since the two wear models adopt different expressions for calculating the wear performance, the attention of this paper is on assessing which one is more suitable for the fast non-Hertzian methods to utilize. The comparison shows that the combination of the USFD wear model with any of the fast non-Hertzian methods agrees better with CONTACT+USFD. In general, ANALYN+FaStrip is the best solution for the simulation of the wheel–rail rolling contact, while STRIPES+FASTSIM can provide better accuracy for the maximum wear depth prediction using the USFD wear model.

“…Similar investigations were also presented by Xu et al. 19 and Ma et al. 20 in terms of quasi-static wheel–turnout contact including a two-point case.…”

Section: Introductionsupporting

confidence: 82%

Assessing the fast non-Hertzian methods based on the simulation of wheel–rail rolling contact and wear distribution

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2019

Self Cite

“…The wheel-rail contact model serves as a link for the interaction between the dynamic model of the vehicle and the high-speed turnout, which includes the geometric calculations of wheel-rail contact and the solution for the wheel-rail rolling contact force. Based on the previous research [1,14], the space trace line method is adopted to calculate the positions of wheel-rail contact points and contact angles in a high-speed railway turnout. The semi-Hertzian method is used to solve the wheel-rail normal contact problem, including the determination of the number of contact points and normal contact forces.…”

Section: Wheel-rail Contactmentioning

confidence: 99%

“…The variation of rail profiles changes the boundary conditions of wheel-rail contact, and the combination of switch rail and stock rail to bear wheel loads together makes multipoint contact more common in railway turnouts. Normal wheel-rail contact situations are disturbed when a wheel transfers from stock rail to switch rail in the switch panel or from wing rail to point rail in the crossing panel [1]. Furthermore, to ensure the structural integrity and stability of railway turnouts, such turnout rails are connected by the shared iron plate of different lengths or the spacer block.…”

Section: Introductionmentioning

confidence: 99%

Stiffness Characteristics of High-Speed Railway Turnout and the Effect on the Dynamic Train-Turnout Interaction

et al. 2016

Shock and Vibration

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Track stiffness in railway turnouts is variable due to differences in structural composition along the longitudinal direction, which will lead to severe dynamic interaction between train and turnout. In this paper, a transient analysis model is presented to investigate the stiffness characteristics of high-speed railway turnouts based on the finite element method and is applied to optimise the stiffness of railway turnouts. Furthermore, the effect of the stiffness variations on the dynamic train-turnout interaction is analysed. The calculation results show that the track stiffness characteristics are similar in the main and diverging line of railway turnout, except for the check rail sections. Due to the existence of shared baseplates and spacer blocks between different rails, the stiffness variations in the crossing panel are most severe in high-speed railway turnouts. The stiffness differences (calculated as the ratio of the maximum and minimum stiffness) of the longitudinal and lateral direction for Chinese number 18 ballasted turnout are 216% and 229%, respectively. The graded stiffness of the tie pads has been redesigned to optimise the stiffness of railway turnout based on the transient analysis model and the stiffness differences of the turnout are decreased. Altogether, the dynamic train-turnout interaction is enhanced remarkably by considering the turnout's stiffness characteristics.

“…ese factors will ultimately lead to serious damage to the components of railway turnout and result in the transmission of noise and vibrations to the external environment. Railway turnouts have therefore become a key part of the railway infrastructure which limits vehicle speeds [3,4]. However, most turnouts on heavy haul railways and existing lines are subject to straight track passing.…”

Section: Introductionmentioning

confidence: 99%

Investigation on Wheel‐Rail Contact and Damage Behavior in a Flange Bearing Frog with Explicit Finite Element Method

Gao

Mathematical Problems in Engineering

Liu

et al. 2019

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Flange bearing frogs are designed to provide continuous rolling surfaces for trains traveling on the through line, but the interaction between wheel and rail in a diverging line is more complex than that for a common crossing, especially including flange bearing mode and multipoint contact during the transition. The wheel load will be transited from tread to flange and back to tread, which will intensify the wheel-rail interaction. In this paper, a numerical procedure is presented for the analysis of wheel-rail rolling contact behavior and damage prediction for the flange bearing frog. The three-dimensional explicit finite element (FE) model of a wheel passing the flange bearing frog is established to obtain the dynamic wheel-rail interaction in both the facing and the trailing move. The evolution of contact forces, the distribution of adhesion-slip regions, and shear surface stress and microslip at the contact patch are revealed. Then, the competition relationship between RCF (rolling contact fatigue) and wear of a flange bearing frog is analyzed. The results of numerical simulations can contribute to an understanding of the mechanism of the transient rolling contact behavior and provide guidance in design optimization for flange bearing frogs.