ELASTIC PLASTIC CONTACT MODEL FOR BIFRACTAL SURFACES

Roughness measurements by atomic force microscopy have shown that the surfaces of magnetic tapes follow two different regimes of fractal structure. For such bifractal surfaces, this paper presents an elastic-plastic contact model. The theory is used to predict the real area of contact of a magnetic tape in contact with a flat hard plane. The trends of both the theory and experiments are in agreement. The theoretical predictions show that for contact pressures between 1 kPa and 10(4) kPa, the fraction of real area of contact in elastic deformation is about 90%. This is in agreement with experimental observations.