Characteristic material behaviors in conical indentation with friction

Abstract

AbstractCharacteristic material behaviors in obtuse‐angled conical indentation for elasto‐viscoplastic solids are explored and discussed. Finite element calculations are carried out for indentation of a rigid sharp conical indenter into a cylindrical body that models a pseudo‐half space, considering the friction between the indenter and the solid. Under low‐friction conditions, it is assumed that breakage of the material by the sharp tip of the indenter occurs and a new surface emerges along the contact interface during indentation. It is revealed that the load required for indentation does not necessarily reach its maximum at the perfect sticking condition, which shows a nonlinear variation from the frictionless condition to the perfect sticking condition. The increase in strain hardening and the decrease in elastic modulus relative to yield strength both reduce the difference between the required loads for different friction conditions. For perfect sticking, the indenter tip is covered by an elastically deforming material cap during indentation similarly to the case of the plane strain wedge indentation. Similarity and discrepancy between the behavior in the conical indentation and that in the plane strain wedge indentation, which is well described by the classical slip‐line field theory, are clarified in detail.