Model for Adhesion-Based Energy Dissipation During Friction

Adhesion influences pure interfacial friction on ideal surfaces when the scale approaches micro- and nano-scales. For non-adhesive surfaces, the adhesion forces are composed of Van der Waals surface forces and the forces resulted from the contact. The van der Waals forces are basically conservative and by themselves do not provide energy dissipation process. The contact forces depend on surface atomic configuration, surface energy distribution, electron interactions, and the real area of contact, and are not conservative in nature, resulting in the fact that pull-off forces are always greater than the snap-on forces. This is referred to as the adhesion hysteresis. In this paper we propose a nanofriction model based on the energy dissipation mechanism of the adhesion hysteresis. We consider the contact of a rigid cylinder on an elastic plane, using the Dugdale approximation. The plane is modeled by continuously distributed elastic springs. For both sliding and rolling contacts, adhesive force at the rear of the cylinder is greater than at the front, which results in frictional resistance and energy dissipation due to excitation of the elastic oscillations. The relationship among adhesion, adhesion hysteresis, and friction is discussed.