
216 Friction-Induced Vibration and Self-Organization
Thus, Roubicek et al. (2008) observed that the coefcient of friction
decreased with increasing temperature during the SAE J2430 friction test,
which is frequently used in the United States for evaluating brake perfor-
mance. This is attributed to physical and chemical changes in the friction
layer that forms on the friction surface (Filip 2002). As it was mentioned ear-
lier, Venkataraman and Sundararajan (2002) found that the dependency of
the coefcient of friction varied within different working ranges of the slid-
ing velocity and load.
Then, Mortazavi et al. (2012) concentrated on the potentia ...