Technical Paper
The Effect of Environmental Humidity and Temperature on Friction Level and Squeal Noise Propensity for Disc Brake Friction Materials
2008-10-12
2008-01-2534
This paper addresses the effect of environmental humidity and temperature on friction level and squeal noise propensity of friction materials when measured in dynamometers at laboratory controlled test conditions. The present work investigates the influence of the environment conditions on the result of noise and friction evaluation of friction material for disc brakes. The relationship among environmental conditions and squeal noise propensity has been studied before by a few authors [1] and is still an open issue when concerns to standard evaluation performed at laboratory controlled conditions. The effect of two main environmental properties for dynamometer testing, cooling air temperature (between 10 and 30°C) and humidity (between 25 to 85%), on friction level and noise were evaluated using a front disc brake. A test matrix, based on SAE J2521, was developed to adequately evaluate these two variables separately into a NVH environmental chamber equipped dynamometer.