Effect of overlapping wheel passages on residual stress in rail corners

There has been recent effort to use different grinding strategies to alter the profile of the high rail in curved track to generate contact stress distributions that minimize the occurrence of near surface shells. The loading of this contact involves significant amounts of lateral tangential tractions. Finite element modeling is used to calculate residual stresses near the gage face/running tread corner in the high rail of curved track which is influenced by the lateral tractions. The modeling focuses on the interaction of contacts that occur at slightly different locations along the gage face/running tread corner. Results include a region of fairly large tri-axial residual tensions just underneath the plastic zone at a depth significantly below the region of maximum shear stress due to elastic contact. These tri-axial tensions are consistent with the occurrence of gage corner shells. A shakedown argument used to describe the physical basis for these residual stresses qualitatively agrees with the finite element calculations. The shakedown argument reveals that the residual tension occurs beneath the plastic zone, leaving them well beneath the maximum shear stress calculated by elastic contact theory.