Elastic-Plastic Contact Conditions for Frictionally Constrained Bodies Under Cyclic Tangential Loading.

A Frictionally constrained condition implies dependence of friction force on tangential displacement amplitude. The condition may occur due to chemical, physical, and/or me-chanical interaction between the contacting suifaces. The condition, sometimes also referred to as the presliding condition or partial slip condition, is characterized under fretting. Under such conditions, various experimental studies indicate the existence of two distinguishable regions, that is, stick region and slip region. In the present study, fric-tionally constrained conditions are identified and the evolutions of stick-slip regions are investigated in detail. Investigations have been performed on self-mated stainless steel and chromium carbide coated suifaces mated against stainless steel, under both vacuum and ambient conditions. Contact conditions prevailing at the contact interface were iden-tified based on the mechanical responses and were correlated with the surface damage observed. Surface degradation has been obsen'ed in the form of microcracks and mate-rial transfer. Detailed numerical analysis has also been performed in order to understand the energy dissipation and the damage mode involved in the surface or subsurface dam-age. It has been observed that under frictionally constrained conditions, the occurrence of annular slip features are mainly due to the junction growth, resulting from elastic-plastic deformation at the contact interface. Ratcheting has been observed as the govern-ing damage mode under cyclic tangential loading condition. [ABSTRACT FROM AUTHOR]