Influence of short thermal cracks on the material behaviour of a railway wheel subjected to repeated rolling

An analysis of whether and how the occurrence of shallow (radial) thermal cracks promotes additional plastic deformation of a mechanically loaded wheel tread is carried out. The study employs numerical simulations of a 2D slice of an elastoplastic railway wheel tread containing thermal (radial) cracks. The cracked wheel material is subjected to repeated passes of a frictional rolling contact load. The effect of the existing thermal cracks on bulk deformation and subsequent rolling contact promoted growth is quantified. Results indicate that thermal cracks of a depth of 0.1 mm have a negligible effect, whereas 1.0 mm cracks significantly decrease the bulk resistance of the wheel material. Further, it is shown how the magnitude of stress, strain and deformation depends on the direction of applied traction.