Indentation of elastic solids with rigid cones

Experimental investigations of the response of several elastic solids, carried out using an instrumented indentation machine, are described. These solids include a natural rubber compound, neoprene, and three different compositions of poly(dimethylsiloxane) (PDMS) when they were indented with tungsten carbide cones of included angles of 60°, 90°, 120° and 136°. It is shown that, except for the case of the 60° cone loading on to the blocks of PDMS (1 : 10) and PDMS (1 : 20), the indentation load versus indenter displacement behaviour of all the elastic solids corresponding to all the conical indenters is well fitted by the 1965 Sneddon theory for frictionless indentations. Video camera sequences of the process of indentation by cones of different included angles into the blocks of PDMS (1 : 10) and PDMS (1 : 20) have also been taken from which measurements of the elastic deformation of the indented surface have been made. It is shown that the magnitude of the elastic deformation of the indented surface clo...