Contact stress and residual stress in the nose rail of a high manganese steel crossing due to wheel contact loading

Abstract

Fatigue failure of a high manganese steel crossing is related to its internal crack initiation and growth, which is affected significantly by the magnitude and distribution pattern of contact stress and residual stress in the crossing. Considering the actual service conditions of a crossing and the accuracy requirement for numerical calculation, a whole model of wheel/crossing/ties and a partial model of wheel/crossing are established using elastic‐plastic finite element method. The distributions of contact stress fields and residual stress fields due to wheel contact loading are studied. The effect of train speed on the residual stress in the nose rail is discussed. The contact stress field shows regular contours in the cross‐section of nose rail and decreases remarkably with increasing distance of the wheel‐crossing contact position. The maximum contact stress is located at the contact surface between wheel and crossing. The maximum residual stress is located at a position of 1.5‐2.0 mm below the surface of the nose rail, rather than at the contact surface of wheel and crossing. In a failed high manganese steel crossing, the dense cracks mainly were observed neither at the position of maximum contact stress (the contact surface between the wheel and the crossing), nor at the position of maximum residual stress (1.5‐2.0 mm below the surface of the nose rail), but around the depth of 0.8‐1.0 mm from the worn surface, which is between the position of maximum contact stress and the position of maximum residual stress. It indicates that the combined effects of the maximum contact stress and the maximum residual stress play important roles in fatigue crack initiation in the nose rail. The size of high residual stress region increases with the increase of the train speed. The maximum residual stress in the nose rail increases remarkably with the increase of the train speed.

Crack formation within a Hadfield manganese steel crossing nose

“…Apart from the larger surface crack, the 3D scans shows that some smaller subsurface cracks are located at various depths. It is suggested that the maximum residual stresses in a crossing occur at certain depths from the contact surface and it is the combination of the contact and residual stresses that can lead to subsurface crack initiations [20]. Within the nose, many of the surface and subsurface cracks are interconnected, whereas some are propagating individually.…”

Parameters Studies on Surface Initiated Rolling Contact Fatigue of Turnout Rails by Three-Level Unreplicated Saturated Factorial Design

“…l is the maximum value of s and j. s is the minimum number of columns in the orthogonal table for evaluating the error variance, j is the maximum positive integer satisfying Equation (11).…”

“…Xin et al [4] presented a finite element model with regard to crossing with a single running wheel-set in order to calculate the dynamic wheel-rail interaction, and studied the generation and fatigue process of RCF cracks of crossing rails based on their model. Researchers from Yanshan University of China [11][12][13] analyzed the wear and fatigue properties of high manganese steel/austenitic steel and bainitic steel materials used for crossings through material tests in order to realize good wear and fatigue resistance. At present, for the calculation of wheel-rail contact information of turnout switches, researchers usually consider a switch rail and a stock rail as a combined part.…”

Continuous assessment of longitudinal temperature force on ballasted track using rail vibration frequency

“…Therefore, destructive methods require much more work than non-destructive methods, and the cost of the former is also higher in the long run. The nondestructive methods mainly include the Barkhausen method, [4][5][6] X-ray method, 7,8 ultrasonic method, 9,10 strain method, 11 and grating method. 12,13 The Barkhausen, X-ray, and ultrasonic methods can introduce uncertainty when used in practice because they are greatly influenced by the material distribution inside the rail and residual stress on the rail surface.…”