An Experimental Investigation of Frictionally-Excited Thermoelastic Instability in Automotive Disk Brakes Under a Drag Brake Application

Abstract

Thermoelastic instability in an automotive disk brake system is investigated experimentally under drag braking conditions. The onset of instability is clearly identifiable through the observation of nonuniformities in temperature measured using embedded thermocouples. A stability boundary is established in temperature/speed space, the critical temperature being attributable to temperature-dependence of the brake pad material properties. It is also found that the form of the resulting unstable perturbations or eigenfunctions changes depending upon the sliding speed and temperature.