Influence of compressive stresses on the Propagation of Surface Shear Cracks in Railroad Rails

Abstract

We study the influence of longitudinal compressive residual stresses on the elastic state of a railroad head damaged by a surface crack under the conditions of rolling contact. For this purpose, we solve a two-dimensional contact problem of the theory of elasticity for a half plane weakened by an edge crack whose lips are in contact with friction under the action of a moving Hertz load on the edge of the half plane and uniform uniaxial compression at infinity. The stress intensity factors are found and the maps of contact of the crack lips are constructed for different values of the operating parameters typical of the wheel–rail system. We determine the most dangerous orientations of the crack susceptible to propagation in the zone of compression by the mechanism of transverse shear.