Crack Detection in Friction Material of Brake Pads

Abstract

Vehicles today may bear little resemblance to their predecessors but one element remains largely unchanged: the disk brake is still the most commonly used braking system for automotive vehicles. Brake pad production is big business and competition has driven the development of new types of friction materials – materials whose properties need careful characterization and this is where impulse excitation comes in. Analysis of the resonant frequencies following impulse excitation is a well-established quality assurance tool for brake pads. It even has its own standard: SAE J2598. The push to develop more environmentally and biologically friendly brake-pad materials has led to the introduction of new friction materials. Some of these materials may however be more prone to cracking either in the production process or during use, thus a simple method is needed to identify cracks in brake pads.