An Analysis of Heat Transfer and Fade in Disk Brakes

The heat transfer and fade characteristics of automotive disk brakes are studied. A distributed model for the disk is employed, with convection from the sides and edge of the disk and conduction to the hub included. Available expimental data for friction coefficient as a function of temperature for two different lining materials is included in the analysis. The heat transfer equations and dynamic equations of the vehicle are solved numerically. Results presented include the effects on brake pad pressure required and on stopping distance of a sequence of repeated stops with cooling perds between each stop. Also included are deceleration versus time curves, sample temperature distributions in the disk, and a study of the manner in which the heat generated in braking is distributed to storage in the disk, conduction to the hub, and convection to the air.