MODELING THE CONTACT RESPONSE OF COATED SYSTEMS

In order to predict the contact-induced deformation and failure behaviour of coated systems, we have constructed a computer model based on a point load acting on an infinite elastic plate (the coating) resting on an elastic foundation (the substrate). The model clearly establishes the importance of the non-linear contribution which the stretching of the coating makes to the stiffness of the system when the deflections are of the order of the coating thickness or greater. This has consequences for the tribological behaviour and response to hardness testing. Further, the model can be formulated in terms of dimensionless quantities which allow the results to be presented in a compact form yet to be applied to a wide range of coated systems.