SELF-EXCITED VIBRATIONS INDUCED BY DRY FRICTION, .1. EXPERIMENTAL-STUDY

An experimental investigation was conducted in the laboratory with a pin-on-disk type sliding apparatus to study self-excited vibrations induced by dry friction. These vibrations are often encountered in practice, with detrimental effects such as excessive wear of components, surface damage, fatigue failure and noise generation. Four different friction regimes are obtained as the normal load is increased. Self-excited vibrations occur in the last regime when the normal load, or equivalently the kinetic coefficient of friction, reaches a certain critical value. The waveforms of the self-excited vibrations are analyzed. A mathematical model of the contact, including non-linear contact stiffness and damping, is obtained based on experimental data. This model of contact mechanics is necessary for stability analysis given in a companion paper. © 1990.