The effect of indenter geometry on the elastic response to indentation

The paper describes various analytical procedures that account for the influence of the geometry of a rigid indenter upon the measured contact compliance of a smooth perfectly elastic half space. The analytical solutions provide a means of interrelating the reaction force, P, and the displacement, h, characteristics in terms of the contact geometry and the reduced elastic modulus E*. The general form is P=gE*h n , where g and n are functions only of the indenter geometry. This relationship is incorporated into a curve-fitting procedure and used to evaluate the influence of the indenter geometry upon the computed modulus of a poly(isobutylene) rubber. The method described provides a viable means of incorporating the imperfections, associated with the geometry of an indenter, into the interpretation of contact compliance data.