ABSTRACT
The first model concepts to describe the adhesion were given by Johnson, Kendall & Roberts (1971) (JKR model) and by Derjaguin, Muller & Toporov (1975) (DMT model). These models are based on the Herzian contact theory (1881) and consider quasi statically the adhesion effects. Thereby, they neglect the influence of separation velocity. Extensions to dynamic contact problem are given by Roberts & Thomas (1975), Roberts (1988) as well as Barquins (1992). They showed that the dynamic work of adhesion, which is the energy per unit area to separate two surfaces, can be a multiple of the quasi-static one for viscoelastic materials. Barquins and Johnson & Greenwood (2002) explain the increase in the adhesion effect with the separation velocity and describe the separation as a crack process in a viscoelastic material. Investigations of Kröger confirm this influence on an adhesion pendulum. There it was shown that remarkable adhesion effects with high separation velocities occur between elastomer and macroscopically rough surfaces like asphalt or corundum. Additional time dependent effects can influence the adhesion effects. Examples are time dependent rearrangements or a restructuring of the boundary layer within the contact. This can lead to an increase of the intermolecular interactions between the contact partners.
