A numerical study of the normal loading–unloading contact behaviors considering yield plateau and strain hardening

Loading–unloading is a ubiquitous phenomenon in engineering applications and an enduring topic in contact mechanics. Yield plateau and strain hardening are essential for material behaviors, but they have not been well considered in contact mechanics. This work developed a three-phase constitutive model to accurately describe the elastoplastic contact behaviors considering both yield plateau and strain hardening, merging the elastic-perfectly plastic and power-law hardening behaviors. The significance of the yield plateau and strain hardening was emphasized, and new empirical formulations of dimensionless contact load, area, and residual interference were presented, expanding the present knowledge of the elastoplastic contact problem.