Temperatures Reached in Disc Brakes

Abstract

A solution is given to the problem of the conduction of heat through an infinite slab bounded by parallel planes, initially at zero temperature, when unit area of each surface is subjected to a flux which decreases linearly with time and loses heat at a rate which is proportional to the temperature at that surface. This solution can be used to determine the transient temperatures reached during disc braking at uniform deceleration if it is assumed that all the heat flows into the disc. Both cooled and uncooled brake discs are considered and typical curves are given showing the agreement between the temperatures determined theoretically and experimentally at the friction surface during single brake applications. The problem of repetitive braking at regular intervals is also discussed and a comparison made between the disc brake and the drum brake under similar conditions. Consideration is also given to the problem when no assumptions are made concerning the manner in which heat is shared between disc and pad.