Asperity contact under creep conditions

For most metal forming processes, friction is generated at contacting asperities and usually attributed to adhesion for the common case of smooth tooling. In certain superplastic forming operations, creep is a major deformation mechanism, and realistic simulations require surface contact models that incorporate creep. In the present work, a single asperity/rigid tool contact under a constant pressure was modeled using an elastic-creep constitutive model. Finite element modeling with a design of experiments methodology was used to characterize the main parameters that affect asperity contact, and through the incorporation of a physics-based model, were used to derive a new contact area expression based on a characteristic time of the asperity deformation.

Automated summary

This study simulated the contact between a single asperity/rigid tool under constant pressure using finite element modeling and design of experiments, and derived a new contact area expression based on characteristic time of asperity deformation.