College of Engineering and Applied Science
Department of Civil Engineering and Mechanics
University of Wisconsin – Milwaukee, U.S.A.

It has been shown that the pre-fracture processes at the meso-level, such as nucleation of microcracks and their subsequent subcritical growth and coalescence, are responsible for accumulation of damage localized in a small volume of the material adjacent to the contact zone. These processes are leading causes of wear associated with repeated contact of two non-elastic bodies under fatigue loading conditions.

Mathematical modeling of the quasi-static crack growth is accomplished by a careful study of the state of stress existing in the vicinity of the instantaneous contact area. Thus, the Hertz problem is extended into a non-elastic domain of material response. Some of the tools used in mathematical modeling of subcritical crack growth and coalescence involve the use of the cohesive zone crack concept and Wnuk’s "final stretch" criterion, which governs the slow stable crack propagation.

(Prof. Dr. V. Popov)