An Experimental Study on Adhesion, Friction and Stick-Slip Phenomena

Abstract

Stick-slip vibration is an important mode of failure in many structural and mechanical systems and that generally seen in the form of jerking, chattering, squeaking, etc. It is shown experimentally that similar to friction, adhesion is also dynamic in nature and that depends on slip velocity and relaxation or hold time. Fracture mechanics analysis of a soft and hard solid interface in the direct shear sliding reveals that energy release rate (ERR) varies periodically during stick-slip motion. However, in the steady sliding regime, ERR first increases to a maximum value at static strength, becomes constant during dynamic sliding and finally, the ERR reaches at the residual strength to a constant value known as work of adhesion. It is also observed during stick-slip motion that a crack always nucleates from the rear end of the block and traverses the entire interface before the slip and is followed by healing of the same interface begins from the front edge of the block. The present study establishes that a relative competition between the crack growth rate and interface healing rate basically controls the frictional behavior of sliding surfaces.