The paper presents the impact of exceeding the railway rails lifespan which usually causes a railway structural failure, thus an accident. The research highlights the rails’s high degradation, especially on the running area, consisting in 60-70% weight loss by advanced wear of the rail, followed by fatigue fracture caused by alternating cyclic stresses that initiates the crack and also by tensile stresses resulting in the crack growth. The chemical composition, structural and mechanical properties were analyzed in order to establish the causes that led to the railway rails rupture.

The critical plane orientations determined with account for maximum value of energy density parameters and the weight function method were compared to experimental fatigue fracture plane orientations. Energy density parameters used in two multiaxial fatigue failure criteria, i.e. (i) criterion of the maximum normal strain energy density on the critical plane and (ii) criterion of the maximum shear strain energy density on the critical plane were employed. In the other method, the weight functions were formed on the basis of energy parameters. These two methods were verified by experimental tests of 1802A steel. The material was subjected to cyclic and random bending, torsion and combined bending with torsion with different coefficients of cross correlation between normal and shear stresses. The calculated results are satisfactory for both methods.