Acoustic emission in friction: influence of driving velocity and normal force

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2019, Tutor: Eduard Vives Santa-EulàliaThe purpose of this work is the study of the acoustic emission occurring when an aluminium block slides at imposed constant velocity over an emery cloth. It is evidenced that amplitude and energy of acoustic emission signals are statistically distributed following a mixed probability law. A criterion to distinguish two types of signals is established. The most abundant type of signals (type 1) follow an exponentially damped power law distribution. And the less abundant signals (type 2) follow a distribution centred at a certain typical value. Type 2 signals occur when the pulling force exhibits local maxima, prior to the sliding event