A Frictionless Normal Contact Model for Flattening Elastoplastic Single Asperity Considering Yield Plateau and Strain Hardening

Contact between solids is a ubiquitous phenomenon in engineering and an enduring topic in tribology. However, material yield plateau and strain hardening are common in ductile metals but rarely considered in contact mechanics. This work develops a three-phase constitutive model that accurately describes the elastic and plastic behaviors considering both yield plateau and strain hardening, and then constructs a finite element model for the contact of a rigid flat and a corresponding elastoplastic hemisphere. The Taguchi method is employed to conduct numerical simulations of material parameters for finding generalized empirical formulations of dimensionless contact load and area versus dimensionless contact interference in the range of ω∗ ≤ 120. The presented empirical formulations demonstrate good accuracy verified with KE, JG, and Ghaednia's models. This work fills the gap that the yield plateau has not ever been explored in contact mechanics and provides a basic model for describing the contact behavior of engineering rough surfaces for ductile metal.