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Polygonal wear is a type of damage commonly observed on the railway wheel tread. It induces wheel-rail impacts and consequent train/track components failure. This study presents a finite element (FE) thermomechanical wheel-rail contact model, which is able to cope with the three possible generation and development mechanisms of polygonal wear: initial defects, thermal effect, and structural dynamics. The polygonal wear-induced impact contact and further development of wear are simulated. The simulated elastic contact solutions are verified against the program CONTACT. Different material properties (elastic, elasto-plastic and elasto-plastic-thermo, i.e. with thermal softening) and initial polygonal profiles are then applied to the FE model to investigate the influence of wheel/rail material and wear amplitude on wheel-rail contact stress and wear development. The simulations indicate that the wheel-rail impact-induced temperature may reach up to 362 ℃ at the contact interface, and the high temperature at the contact area influences wheel-rail contact stress and wear depth. • An innovative thermomechanical FE model is presented to study polygonal wear growth. • The simulated contact solutions are verified against the program CONTACT. • Using elastic material models causes overestimation of contact stress and wear depth. • Incorporating thermal effects is crucial for wear predication with high slip ratio. • The simulated contact temperature reaches up to 362 ℃ at the wheel-rail interface. [ABSTRACT FROM AUTHOR]

As traffic density and axle loads increase, the macroscopic wheel-rail contact can lead to severe rail wear. This paper constructs a multi-scale analysis framework from macroscopic force characteristics to microscopic wear mechanisms based on explicit finite element methods and molecular dynamics models. The study shows that the mutual proximity and annihilation of reverse dislocations in the rail material under the action of wheel-rail forces is an important cause of grain boundary fragmentation, while the proliferation of dislocations on the Subsurface leads to work hardening of the rail. The analytical framework proposed in this paper achieves a multiscale correlation between wheel-rail macroscopic contact and material microscopic response, and the conclusions obtained reveal the microscopic wear mechanism of rail materials. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to analyze the influence of the load direction and the phenomenon of wear on rolling contact fatigue crack growth. For this purpose, a UIC60 rail with accurate geometry using FEM is studied. In this regard, a three-dimensional finite element model is provided. The maximum stress caused by wheel/rail contact for a new/worn wheel profiles was obtained using such model. Then, using Franc 3D software, during stress analysis for different situations of wheel, different values of stress intensity factors are obtained. The behavior of crack under fatigue loading was studied using a three-dimensional modeling. [ABSTRACT FROM AUTHOR]

A multi-step FE modeling strategy has been proposed to predict the temperature evolution, thermo-mechanical response, surface fatigue life and wear behaviors in railway rail for multi wheel passages. Equivalent contact pressure and heat source were coupled and moved simultaneously on rail surface to achieve a balanced advantage of low computational cost and high accuracy. Wheel configuration at locomotive plays a significant role on rail temperature. The highest temperature of 776.05 °C was developed with a slip ratio of 9.43% after 9 wheel passages. Rolling contact fatigue life of rail material decreased quickly with slip ratio due to significant thermal softening effect. Transition from mild to severe wear was found at slip ratio of 2.38% according to the corresponding rail flash temperatures. • A modelfor multi wheel passages of train locomotives considering both contact pressure and thermal effects was proposed. • Practical scenario of two locomotives was introduced to study the temperature evolution on rail surface. • Relation between slip ratio and rolling contact fatigue life of rail material was predicted. • Wear of rail was mild when slip ratio was ≤2.38% but transited into severe wear when slip ratio was higher. [ABSTRACT FROM AUTHOR]