Fe micro-models to study contact states, stresses and failure mechanisms in a polymer composite subjected to a sliding steel asperity

FE micro-models have been developed in order to determine contact, stress and strain conditions produced by a steel asperity sliding on the surface of a fibre-reinforced polymer composite. Three cases were studied, i.e. a normal, a parallel and an anti-parallel fibre orientation relative to the sliding direction. In order to get more realistic simulation results about the failure conditions in the composite structure, FE contact macro/micro-models were used, contrary to the so far widely applied anisotropic analytical or numerical macro-models. To model a “micro-environment” as part of a “macro-environment”, the displacement coupling technique was introduced. On the basis of the stress results, conclusions were drawn on the possible wear mechanisms of the fibre-reinforced polymer composites. For each fibre orientation, surface failure of the matrix material occurs due to high shear stresses. The other characteristic source of failure is fibre/matrix debonding, eventually followed by fibre cracking events.