Brake Pad Surface Topography Part I: Contact Pressure Distribution

Recent studies carried out at the University of Liverpool showed that there was a variation in static contact pressure distributions on two new sets of pads even though they were tested with the same brake system under the same pressure. One of the possible reasons for this variation is due to brake pad surface topography.

This paper investigates the effects of brake pad topography on contact pressure distributions. Pressurex^®, pressure indicating films are used to measure static contact pressure distribution. A detailed 3-D finite element model of a disc brake is also developed and takes into account pad surface profiles. A linear gauge is used to measure brake pad topography. Six different pad configurations are studied in this investigation. Results from the investigation could provide a better explanation of the variation in contact pressure distribution and in turn squeal generation.