Modelling of the fracture of a railway wheel

Fatigue crack propagation in railway wheels occurs under mixed mode (I-II) conditions, and frequently the crack is initiated at some subsurface small defect.This paper presents the modelling of the propagation of a crack initiated inside the tire of a Spanish AVE train wheel.The work is based upon the time dependent stress state of the wheel, and mechanical properties of the wheel steel measured using Compact Tension Shear specimens. In order to generate data for use in the simulation of the wheel fracture, mixed mode I-II fatigue crack growth tests were performed on 9 mm thick CTS specimens using a servo-hydraulic MTS fatigue testing machine. These tests were modelled using the finite elements method. The crack propagation direction (angle) was experimentally measured and numerically calculated, and the obtained results were then compared in order to validate the used numerical techniques.The data obtained using conventional Fracture Mechanics specimens was then used to model crack growth in the wheel. The modelled crack growth, up to final fracture in the wheel, is consistent with the expectation for the type of initial damage considered