Calculation of Average Coefficient of Friction During Braking

This paper demonstrates that the time-domain average of coefficient of friction (COF) widely in use today does not serve as a reliable indication of a system's braking capability. For a given braking system, it may lead to large error in predicted stopping distance. When used in lining selection, it may lead to incorrect ranking of various linings' friction level.

A new method for calculating the average of friction coefficient is proposed and compared with the time-domain average COF. A detailed error analysis is given for two special cases.