WTC2005-64357 RESOLVING THE CONTRADICTION OF ASPERITIES PLASTIC TO ELASTIC MODE TRANSITION IN CURRENT CONTACT MODELS OF FRACTAL ROUGH SURFACES

ABSTRACT The elastic-plastic contact model of fractal rough surfaces offered by Majumdar and Bushan in 1991 (the MB model) is revisited. According to the MB model, the contact mode of a single fractal asperity transfers from plastic to elastic when the load is increased, and the asperity's contact area grows and becomes larger than a critical area, which is scale independent. This surprising result of the MB model is in contrast with classical contact mechanics where an increase of contact area due to increased load, is associated with a transition from elastic to plastic contact. The present study describes a revised elastic-plastic contact model of a single fractal asperity showing that the critical area is scale dependent, contrary to the MB model prediction. The new model also shows that a fractal asperity behaves as would be expected from classical contact mechanics namely, as the load and contact area increase a transition from elastic to plastic contact takes place in this order. INTRODUCTION The pioneering fractal contact model of M

Analytical approximations in modeling contacting rough surfaces

A critical examination of the analytical solution presented in the classic paper o

Revisiting the Cattaneo–Mindlin Concept of Interfacial Slip in

Abstract. The Cattaneo-Mindlin concept of interfacial slip in tangentially loade

IJTC2009-15054 REVISITING THE CATTANEO-MINDLIN CONCEPT OF INTERFACIAL SLIP IN TANGENTIALLY LOADED COMPLIANT BODIES

ABSTRACT The Cattaneo-Mindlin concept of interfacial slip in tangentially loaded compliant bodies is revisited and its basic simplifying assumptions are critically examined. It is shown that these assumptions, which, in the absence of modern numerical techniques, were essential in 1949 to enable an elegant quantitative solution of the basic problem of presliding between contacting bodies, are actually non physical. An alternative approach to the same problem that is based on treating sliding inception as a failure mode involving material plastic yield is discussed. This alternative approach was suggested even before 1949 but for the same lack of modern numerical techniques could only be promoted qualitatively. Some recent theoretical models, that are based on this earlier alternative approach, and in which the simplifying assumptions of the Cattaneo-Mindlin concept were completely relaxed are described along with their experimental verification. It is shown that the pre-sliding problem between contacting bodies can be accurately solved by these models using realistic physical assumptions and failure criterion