Review article

The paper studies the effect of the shape of the internal transverse defect on the fatigue crack resistance of the beam. The beam on a solid elastic foundation with a cross-section in the form of an unequal I-beam is subjected to cyclic bending by concentrated force. Various schematizations of the defect are considered, namely, a crack of circular shape, elliptical, oval, and oval of the fourth degree shape. A comparative analysis of stress intensity factors is performed. The dependence of the permissible number of loading cycles on the applied force for circular and oval cracks has been established, taking into account the boundaries of the body. The proposed calculation scheme is used to estimate the residual life of railway rails.