SIMPLE-MODEL FOR DRY FRICTION

The basis of dry friction is discussed using an independent oscillator model with longitudinal motion. This simple system is treated both nu merically and with analytical methods. At vanishing velocity a sliding dry friction force is calculated which is smaller than the pinning fo rce. At finite but not too large velocities the system displays bifurc ation, chaotic motion, resonances at fractional and multiple frequenci es of the oscillator, and hysteresis. Dry friction results from these complicated features. This force varies rapidly with velocity within t his range, however, with a roughly constant mean value.