Plasticity in fretting of coated substrates

A detailed analysis is performed of the plastic deformation in a metal subs trate fretted by a flat-bottomed circular peg under steady normal load and cyclic tangential load. The substrate is coated with a thin layer of soft m etal. Two limiting asymptotic problems are identified which characterize sm all scale yielding behavior in the substrate in the vicinity of the corners of the peg. Deformation within the plastic zone is characterized, includin g regions of elastic shakedown, steady reversed cyclic plastic straining, a nd strain ratchetting. Implications for nucleation of fretting cracks are d iscussed. (C) 1998 Elsevier Science Ltd. All rights reserved.