SOLUTION OF FRICTIONAL CONTACT PROBLEMS USING ILU AND COARSE FINE PRECONDITIONERS/

In this paper we discuss the efficiency of two preconditioners (incomp lete factorization and coarse/fine factorization) to solve non symmetr ic and ill-conditioned linear systems arising from the resolution of f rictional contact problems. Mixed formulation is introduced and genera lized Newton method is reviewed. We describe a multilevel interpolatio n adapted to the coarse/fine preconditioner. Numerical examples are pr oposed to show strong and weak points associated to both methods and o ptimal approximations are given to improve their efficiency.