Comparison of SIF solutions for cracks under rotating bending and their impact upon propagation lifetime of railway axles

The stress intensity factor (SIF) is a crucial input parameter for the definition of the inspection intervals based on the damage tolerance approach. In the present work the applicability and precision of existing analytical stress intensity factor solutions for the cracks in railway axle geometries, subjected to rotary bending and residual stresses is discussed, by comparison with a reference set of solutions obtained from finite element (FE) analyses. Both the SIFs and the crack shape evolution are considered, comparing the predicted crack shape growth, from FE and analytical solutions, with a series of experimental data from the literature. Finally, the effect of the different approximations for the propagation lifetime and non-destructive tests (NDT) reliability of railway axles is discussed.