On The Adequate Representation Of Velocity Fields In A Narrow Layer Near Maximum Friction Surfaces

Abstract

In the case of pressure‐independent plasticity, the maximum friction law postulates that the friction stress is equal to the shear yield stress of the material. Its distinguished feature is that it leads to the largest friction stress among all possible friction laws. Due to a significant uncertainty in the modelling of deformation processes because of the absence of a physically based model for friction, this feature of the maximum friction law can be very useful for evaluating process parameters. The present paper concerns with an adequate representation of velocity fields in the vicinity of maximum friction surfaces (surfaces where the maximum friction law is valid). Various constitutive models that are usually adopted to describe metal forming processes are considered. In the case of pressure‐dependent plasticity, appropriate generalizations of the maximum friction law of pressure‐independent plasticity are used.