COMPARISON BETWEEN ANALYTICAL AND FEM CALCULATIONS FOR THE CONTACT PROBLEM OF SPHERICAL INDENTERS ON LAYERED MATERIALS

An analytical solution and a finite element calculation have been util ised to investigate the contact stresses due to elastic spherical inde ntation into coating/substrate systems. Such calculated stress distrib utions may be used for the optimal design of layer systems as well as, together with experimental penetration-force curves, to determine qua ntitative measures for toughness and adhesion of the film. Both approa ches were compared using various systems composed of a higher modulus surface coating on a relatively low modulus substrate. It was found th at both methods agree very well and yield adequate stress distribution s for various film thicknesses. Here we show the radial stress compone nt Yy = sigma(r) for six different systems.