The cyclic loading as a result of the stick-slip motion

We investigate the influence of oscillating normal force on the frictional sliding. Frictional sliding in the case of a simple mass-spring model of Burridge and Knopoff type demonstrates stick-slip even when the friction coefficient is constant. Oscillations of the normal force in this case do not produce noticeable changes in the stick-slip sliding mode. A completely different picture is observed when the oscillations of normal force are applied to the system, which is in the state of steady sliding. In this case the normal oscillations turn the steady sliding into stick slip. A special case is observed when the normal force oscillates with the eigen frequency of the stick-slip motion. Then, no matter how small the amplitude of oscillations is the system reaches the same final stick-slip regime. The time required to reach this limiting regime is inversely proportional to the amplitude of oscillations of the normal force. © (2014) Trans Tech Publications, Switzerland.