Print Email Facebook Twitter Nucleation of squat cracks in rail, calculation of crack initiation angles in three dimensions Title Nucleation of squat cracks in rail, calculation of crack initiation angles in three dimensions Author Naeimi, M. Li, Z. Dollevoet, R.P.B.J. Faculty Civil Engineering and Geosciences Department Structural Engineering Date 2015-07-01 Abstract A numerical model of wheel-track system is developed for nucleation of squat-type fatigue cracks in rail material. The model is used for estimating the angles of squat cracks in three dimensions. Contact mechanics and multi-axial fatigue analysis are combined to study the crack initiation mechanism in rails. Nonlinear material properties, actual wheel-rail geometries and realistic loading conditions are considered in the modelling process. Using a 3D explicit finite element analysis the transient rolling contact behaviour of wheel on rail is simulated. Employing the critical plane concept, the material points with the largest possibility of crack initiation are determined; based on which, the 3D orientations/angles of the possible squat cracks are estimated. Numerical estimations are compared with sample results of experimental observations on a rail specimen with squat from the site. The findings suggest a proper agreement between results of modelling and experiment. It is observed that squat cracks initiate at an in-plane angle around 13°-22° relative to the rail surface. The initiation angle seen on surface plane is calculated around 29°-48°, while the crack tend to initiate in angles around 25°-31° in the rail cross-section. To reference this document use: http://resolver.tudelft.nl/uuid:56802331-af28-49f3-b29d-8f2630c48976 Publisher IOP Publishing ISSN 1742-6588 Source https://doi.org/10.1088/1742-6596/628/1/012043 Source Journal of Physics: Conference Series, 628 (1), 2015; 11th International Conference on Damage Assessment of Structures (DAMAS 2015) Part of collection Institutional Repository Document type conference paper Rights (c) Creative Commons BY Files PDF 318643_.pdf 3.47 MB Close viewer /islandora/object/uuid:56802331-af28-49f3-b29d-8f2630c48976/datastream/OBJ/view