Estimating the real contact area between sliding surfaces by means of a modified OFC model

A modification of the Olami, Feder, Christensen (OFC) spring-block model in order to model the real contact area of two rigid bodies sliding pass each other, is introduced. The modification is based on relaxing the assumption of global physical contact and uniform maximal static friction. The real contact area is estimated by means of specific distribution parameters of the emerged distribution functions of the slip sizes (incremental displacements). It is shown that for a wide range of model parameters there is a clear monotonic relationship between the real contact area and the distribution parameters. As a result, the proposed model allows for the determination of the real contact area in an indirect way through the experimental determination of the probability density function of the slip sizes of one body as it moves relative to the other.