Detailed Contact Geometry Processing for 3D Wheel and Rail Surfaces

The CONTACT software is extended to incorporate the full 3D shape of rails and wheels in the simulation of vehicle-track interaction, covering on the one hand rails with longitudinal profile variation (switches and crossings, turnouts), and on the other hand localized defects like wheel flats and squats.The new version of CONTACT is embedded in SIMPACK Rail using on-line integration, replacing the original methods used for the wheel-rail contact force calculation.A measured wheel flat is taken as an example, computing the impact forces for a range of circumstances.Whereas previous works typically applied a radius variation across the whole width of the wheel, the full 3D shape of the flat is included here accounting for the actual flat depth at the lateral positions on the wheel where contact occurs.The detailed stress histories computed may be used to study the evolution of the wheel flat in time.