The effect of proximity of a rail end in elastic-plastic contact between a wheel and a rail

Abstract

This paper investigates the effects of a free rail end on the contact stress distribution near the rail end by employing elastic-plastic finite element methods. The contact elements were used to simulate the interaction between a wheel and a rail. A plane strain model was used in this study. Variations in contact stress fields at various contact points near the rail end were compared. The availability of the Hertz contact theory in the region near the rail end was also investigated. The numerical results indicated that the contact stress distributions around the rail end are sensitive to the contact distance. The location of the maximum von Mises stress was shifted to the contact surface as the contact point moves close to the rail end. Results also show that the plastic zone size and the von Mises stress are increased gradually and extend to the rail end as the contact point moves near the rail end. A higher stress, larger deflection and serious plastic deformation occurring at the rail end may lead to deterioration and delamination at the rail end.

Minimization of railhead edge stresses through shape optimization

“…early material deterioration. The loss of stiffness closer to the free edge shown in Figure 8 is in agreement with the results discussed in Hanson and Keer (1989) and Chen (2003). Figure 9 shows the equivalent stress field close to the end at load F. The optimal maximum von Mises stress is approximately 0.688 P 0 , reduced from 0.692 P 0 for the one in the original shape with a sharp corner.…”

“…The unsupported rail edge under a static wheel load was examined by Chen and Kuang (2002) for frictionless contact using a three-dimensional FEM and by Chen (2003) using a two-dimensional elastic-plastic plane strain FEM. The contact pressure and stress variations in the proximity of the free edge were reported, with the maximum von Mises stress increasing and shifting to the edge corner as the wheel moved to the rail end.…”

Ratchetting damage of railhead material of gapped rail joints with reference to free rail end effects

“…A peak pressure of 2000 MPa on IRJs was used elsewhere. 9 In the ABAQUS mesh module, eight-node fully integrated tri-linear brick elements (C3D8) were considered for all components in the solid modelling zone. This type of element was considered because it is widely used in elastic-plastic material deformation.…”

“…2,[5][6][7][8] However, only a few research studies have been conducted considering GRJs. Initially, Chen 9 employed an elastic-plastic plain strain finite element method to investigate the effects of a free rail end on wheel/rail contact stress distribution. The simulated results suggested that contact stress distributions around the rail end are sensitive to the contact distance from the free end.…”

“…There is no indication of railhead material damage and patterns of damage in the railhead sub-surface in the vicinity of endposts. 9,10 Because of the sharp rise of contact pressure and severe plastic deformation at the free rail ends of rail joints, there are a few studies to reduce the railhead edge stress 11 and to quantify the strain fields at the discontinuous railhead edges. 12,13 A detailed understanding of damage mechanisms is necessary to increase the fatigue life of GRJs.…”