How Does Dissipation Affect the Transition from Static to Dynamic Macroscopic Friction?

• Published in: Lubricants Vol. 3; no. 2; pp. 311 - 331
• Main Authors: Gershenzon, Naum I, Bambakidis, Gust, Skinner, Thomas E
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-06-2015
• Subjects: Dissipation; dry macroscopic friction; Dynamics; Earthquakes; Frenkel-Kontorova model; Friction; Mathematical models; Rupture; rupture velocity; sine-Gordon equation; Slip; slip pulse; Slip velocity; transition process
• ISSN: 2075-4442; 2075-4442
• DOI: 10.3390/lubricants3020311

Description of the transitional process from a static to a dynamic frictional regime is a fundamental problem of modern physics. Previously, we developed a model based on the well-known Frenkel-Kontorova model to describe dry macroscopic friction. Here, this model has been modified to include the effect of dissipation in derived relations between the kinematic and dynamic parameters of a transition process. The main (somewhat counterintuitive) result is a demonstration that the rupture (i.e., detachment front) velocity of the slip pulse which arises during the transition does not depend on friction. The only parameter (besides the elastic and plastic properties of the medium) controlling the rupture velocity is the shear to normal stress ratio. In contrast to the rupture velocity, the slip velocity does depend on friction. The model we have developed describes these processes over a wide range of rupture and slip velocities (up to 7 orders of magnitude) allowing, in particular, the consideration of seismic events ranging from regular earthquakes, with rupture velocities on the order of a few km/s, to slow slip events, with rupture velocities of a few km/day.