An important class of structural mechanics problems deals with the stress analysis of bodies in contact. A contact problem occurs when at least two bodies not mechanically joined touch each other without becoming rigidly attached. In most cases, high stress concentrations are developed in the contact areas. This fact and the presence of friction and wear often cause crack initiation and fretting fatigue. Thus, the analysis of elastic bodies in contact is a common concern in engineering practice and it is important to include the effects of friction in this analysis.