Classification and consideration of plasticity phenomena in wheel-rail contact modelling

Physical processes within the wheel-rail contact greatly influence the vehicle-track interaction in railway operation. Thus, prediction models are of great importance taking plasticity phenomena appropriately into account. Such plasticity phenomena generally occur in railway operation. Therefore, a new classification of plasticity phenomena is introduced: (1) "global" plastification in the order of hundreds of microns up to millimetres due to the general loading situation and (2) "tribological" plastification in the order of microns caused by surface effects (e.g. roughness) which is always accompanied by the wearing process. "Global" plastification occurs only during the first cycles and always gets into elastic shakedown, while "tribological" plasticity is a continuous process never reaching elastic shakedown. State of the art models do not take these effects sufficiently into account. Hence, a new overall wheel-rail contact and damage model (OCD model) has been developed.