Frictional dissipation in stick-slip sliding.

Area of Science:

• Tribology
• Materials Science
• Fluid Dynamics

Background:

• Stick-slip sliding is a common phenomenon in tribology.
• Understanding energy dissipation mechanisms is crucial for predicting friction and wear.
• Previous studies suggested significant energy dissipation occurs at the instant of stick.

Purpose of the Study:

• To investigate the time variation of frictional force during stick-slip sliding.
• To quantify energy dissipation during both slip and stick phases.
• To clarify the dominant mechanism of energy dissipation in confined liquid films.

Main Methods:

• High time and force resolution measurements of frictional force.
• Analysis of energy dissipation during stick-slip events.
• Modeling of viscous heating in a shear-melted confined liquid film.

Main Results:

• Energy dissipation was observed during both slip and stick phases.
• Over 90% of the total energy dissipation occurs during the slip phase.
• Viscous heating of the confined shear-melted film is the primary dissipation mechanism.

Conclusions:

• The dominant energy dissipation mechanism in this system is viscous heating during slip.
• Only a small fraction of energy is dissipated at the instant of stick.
• Findings challenge previous assumptions about energy dissipation in stick-slip events.