Finite element analysis of the indentation of thick coatings by a cylindrical indenter

The finite element code ABACUS was used to study the behaviour of an elastic layer firmly attached to a rigid substrate when indented by a cylindrical elastic indenter, in terms of the induced contact stresses within its thickness and at its interface with the substrate. Frictionless type of contact and various thicknesses of the layer as well as ratios of the respective stiffness of the indenter and layer were considered, when a uniformly distributed load was applied along the indenter. The variation of the normal components of the stress at points along both indenter-layer and layer-substrate interfaces showed the development of significant tensile stresses which could affect the performance of the layer. An increase of the maximum contact pressure when E(i)/E(c) < 10 was also observed, with a less significant effect of the h/R ratio. The evaluation of the shear stresses along the layer-substrate interface has shown that a thinner and more rigid layer contributes to their increase. Finally, two empirical equations were developed for a quick and accurate estimate of the half-width of the indenter-layer contact area, and the depth of the indentation.