Propagation analysis of rail three dimensional surface crack based on ABAQUS/FRANC3D

DOI:	10.11809/bqzbgcxb2024.02.032
Keywords:	3D crack propagation;wheel rail loads; stress intensity factor; propagation path; FRANC3D
Abstract:	To analyze the fatigue propagation path and stress intensity factor changes of three dimensional surface cracks on steel rails under wheel rail loads, and to study the damage mechanism of rail peeling off blocks. This article uses Fortran language to write user subroutines DLOAD and UTRACLOAD to apply wheel rail contact stress. The finite element software ABAQUS and FRANC3D are used to simulate the movement of wheels on the rail and analyze the stress intensity factor of three dimensional surface cracks on the rail as a function of wheel movement. Based on the PARIS formula and the maximum circumferential stress criterion, the fatigue propagation behavior of three dimensional surface cracks on the rail is analyzed. The results indicate that when the wheel rail load is only Hertz contact pressure, the wheel rolls over the surface of the rail. The deeper the crack front edge is from the surface of the rail, the more likely it is to propagate. The crack mainly propagates in the depth direction of the rail, which can turn a semi circular crack into an elliptical crack with a long axis in the depth direction; When the wheel rail load is combined with Hertz contact pressure and sliding friction force, the equivalent stress intensity factor Keq of the surface crack increases with the increase of the number of wheel cycles. The action of the wheel will make the front edge of the crack closer to the surface of the rail more prone to propagation. The crack mainly extends towards the width direction of the rail, transforming a semi circular crack into a complex shape of a long axis near elliptical crack in the width direction of the rail.
Published:	2024-02-28
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