Development of a friction law respecting plastic surface smoothing

摘要

Friction has a significant effect on the metal forming. This is in particular true for the emerging sheet-bulk metal forming process. Therefore an adequate friction law is necessary for the accurate Finite-Element modelling of the process. This friction law has to incorporate a smooth transition from the Coulomb friction law for low contact pressures to a Tresca friction law for high contact pressures. Furthermore the plastic smoothing of surface roughness has to be taken into account. A friction law fulfilling these requirements is developed based on the results of an elastic-plastic halfspace contact model. This model is verified and calibrated experimentally. Its ability to model the changes in the roughness parameters as well as the Abbott curves in normal contact is demonstrated.