Subsurface crack face displacements in railway wheels

In a railway wheel subsurface cracks may form at macroscopic defects under the wheel tread, propagate and, if not managed, cause catastrophic wheel failures. The deformation of such subsurface cracks under rolling contact conditions is the main issue of the current paper. Parametric studies are carried out with a two-dimensional elasto-plastic finite element (FE) model of a part of a wheel containing a subsurface crack. The purpose of the simulation is to study crack face displacements under varying conditions. The influence of crack length, crack location (depth), crack face friction, as well as wheel/rail contact load magnitude and contact geometry is investigated. The numerical results show that mode I deformations are negligible. Further, load magnitudes and contact geometry play crucial roles for the relative tangential crack face displacements. The current study of deformation of subsurface cracks under rolling contact conditions will form the basis for future studies on crack growth prediction.