Flat-ended rebound indentation test for assessing viability of articular cartilage: Application of the viscoelastic layer model

TL;DR

This paper develops an analytical model for a flat-ended rebound indentation test to evaluate articular cartilage viability, revealing that rebound displacement is independent of certain material properties.

Contribution

It introduces closed-form expressions for contact force and displacement in a viscoelastic model, enhancing understanding of cartilage mechanical behavior during indentation testing.

Findings

Rebound displacement is independent of elastic modulus and Poisson's ratio.

Analytical expressions are derived for contact force and displacement.

Model application aids in assessing cartilage viability.

Abstract

The rebound indentation test consisting of the displacement-controlled and load-controlled stages is considered for a frictionless cylindrical flat-ended indenter. The mechanical behavior of an articular cartilage layer sample is modeled in the framework of viscoelastic model with time-independent Poisson's ratio. Closed-form analytical expressions for the contact force (in the displacement controlled stage) and for the indentation displacement (in the load-controlled stage) are presented for an arbitrary viscoelastic solid model. The case of standard viscoelastic solid model is considered in detail. It has been established that the rebound displacement (that is the indentation displacement in the load-controlled stage) does not depend on the relaxed elastic modulus and Poisson's ratio as well as on the layer's thickness.