a1 School of Mathematical Sciences, The Australian National University, Canberra, ACT 0200, Australia.
Friction problems involving “dry” or “static” friction can be difficult to solve numerically due to the existence of discontinuities in the differential equations appearing in the right-hand side. Conventional methods only give first-order accuracy at best; some methods based on stiff solvers can obtain high order accuracy. The previous method of the author  is extended to deal with friction problems involving multiple contact surfaces.
(Received August 13 1989)
(Revised March 31 1994)