Theoretical models for surface mobility are derived using two alternat
ive approaches: time averaged input power and effective mobility. The
surface mobility of a circular contact area of an infinite plate is in
vestigated for both uniform conphase contact force and uniform conphas
e contact velocity. In the latter case the mixed boundary value proble
m is circumvented by using a discretized model to find the force distr
ibution. The theoretical values of surface mobility for a circular are
a with uniform conphase contact velocity are compared to experimental
measurements made on a simulated infinite plate. (C) 1997 Academic Pre
ss Limited.