Residual stresses in rails due to roll straightening

Abstract

The knowledge of residual stresses in rails due to roll straightening has become increasingly important for the evaluation of the fatigue behaviour of rails. The residual stresses are induced both by the bending process and the roll contact leading to a very complicated distribution especially near those parts of the surface where the roll contact had taken place. So far, no clear picture has emerged with respect to the residual stress field, either from experiments or from simulations. This study intends to clarify the residual stress distribution by simulation with a fully three‐dimensional model taking into account both the bending and contact process. This work shows that especially in those areas where the roll contact happens compressive residual longitudinal stresses appear on the surface. Furthermore, a very steep gradient of the residual longitudinal stress distribution near the surface is observed which is reported also in very recent X‐ray and neutron diffraction experimental investigations.