The relationship between plastic zone and contact radius during indentation experiment for strain-hardened materials

In this study, the ratio f of the plastic zone radius, a_PZ, to the contact radius, a_c, for different material properties and at various indentation depths was investigated using a three-dimensional finite element model for strain hardening materials. The effective indentation radius and f were determined via the statistical volume of plastic zone. It was found that f is significantly influenced by material properties, such as yield strength, Young’s modulus, strain hardening exponent and Poisson’s ratio, and less influenced by the indentation depth. A relationship between f and the material properties was proposed.