Rolling contact fatigue of three crossing nose materials—Multiscale FE approach

• Published in: Wear 2014-06, Vol.314 (1-2), p.69-77
• Main Authors: Pletz, M., Daves, W., Yao, W., Ossberger, H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Contact mechanics; Contact of materials. Friction. Wear; Crossings; Dynamics; Exact sciences and technology; Fractures; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Rolling contact fatigue; Surface cracks
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2013.11.013

In this work finite element models at different length scales are applied to predict the performance of three different crossing materials (Manganese steel, Hardox and Marage 300) in view of the development of rolling contact fatigue (RCF) cracks. A model of the whole crossing (crossing model) is used for the calculation of the dynamic forces and movements of wheel and crossing. For the prediction of RCF repeated loadings have to be calculated, but only a reduced model permits a sufficiently fine mesh and reasonable computing times. Therefore, a simplified model of the wheel and the crossing nose (impact model) is developed, which uses the dynamic movements of the crossing model as boundary conditions. The accumulation of plastic strains in the crossing, the build-up of residual stresses and the geometric adaption of the crossing to the loads is studied for 81 load cycles. The contact pressures, shear stresses and residual stresses of the impact model with the adapted geometries of the 81st cycle are applied to a two-dimensional model with a surface crack (crack model). Using data from measured crack growth curves, the three materials can be compared in terms of crack development and growth. •Material selection for crossing noses needs models on different length scales.•The shape of the crossing nose plastically adapts towards the wheel geometry.•Plastic adaption of crossing noses can reduce contact stresses drastically.•Residual stresses reduce the crack tip loading by up to 60%.