Stress gradient effects in surface initiated rolling contact fatigue of rails and wheels
Artikel i vetenskaplig tidskrift, 2016

The paper investigates gradient effects, which relate to how highly stressed regions should be dealt with in fatigue design analyses. In particular stress gradients in rolling contact are investigated with a focus on differences in response between full and partial slip conditions. To this end the multiaxial state of stress beneath a wheel–rail contact featuring full or partial slip is quantified using a multiaxial equivalent stress criterion. A comparative study shows that the significant differences in peak interfacial shear stress magnitudes between full and partial slip conditions are significantly reduced when translated to equivalent stress magnitudes. An innovative procedure to quantify the gradient effects by comparing the multiaxial contact stress field to uniaxial conditions is developed and employed. For the studied cases stress gradients beneath the frictional contact were found to be similar to stress gradients outside a uniaxially loaded large plate featuring a small hole with a radius in the order of 0.5–0.7 mm. The study concludes that the use of local magnitudes of interfacial shear stress in the analysis of surface initiated rolling contact fatigue under partial slip conditions is conservative. The analysis framework established in the current study can be used to estimate the level of conservativeness.

Stress gradient effect

Notch sensitivity factor

Equivalent stress criterion

Rolling contact fatigue

Författare

Anders Ekberg

Dynamik

Elena Kabo

Chalmers, Tillämpad mekanik, Material- och beräkningsmekanik

Roger Lundén

Dynamik

Motohide Matsui

Railway Technical Research Institute

Wear

0043-1648 (ISSN)

Vol. 366-367 188-193

Drivkrafter

Hållbar utveckling

Innovation och entreprenörskap

Ämneskategorier

Tribologi

Teknisk mekanik

Annan materialteknik

Styrkeområden

Transport

DOI

10.1016/j.wear.2016.04.027