Influence of Flattening in the Zone of Welded Joints of Railroad Track on Contact Interaction in the Wheel–Rail System

— The wheel–rail interaction during rolling along a straight railroad track section with and without the rail flattening effect is modeled. Rail flattening is used to describe a defect that occurs in the area of a welded rail joint. The model takes into account an increase in the load during dynamic impactless interaction in the region of welded joints, change in the configuration of the contact region, and existence of stick and slip subregions during rolling. The contact characteristics and stress states of the rail are compared for different relative longitudinal slip and in the presence and absence of track flattening of two characteristic sizes. An analysis of internal stresses shows that an increase in the relative longitudinal slip leads to an increase in the maximal tangential stresses near the surface. The results of analyzing contact pressures and tangential stresses show that, with an increase in the flattening depth, the depth wise distribution of maximal tangential stresses becomes more uniform.