Abstract
KEYWORDS – creep groan, stick-slip, tribometer, low frequency noise, slip power.
ABSTRACT Creep groan is a low frequency noise generated by the stick-slip phenomenon that occurs when moderate brake pressure is applied between the surfaces of the brake disc and brake pad in a low-speed vehicle. It is mainly observed as a structure-borne phenomenon and generally occurs when a vehicle is starting to move from a complete static condition or as it slowly comes to a stop when driving.
The investigations discussed in this paper combine in-vehicle tests and laboratory-scaled tribometer tests. Using a scaled laboratory tribometer eliminates the influence of the brake system and vehicle suspension and allows for a highly flexible design of test procedure, including controlled variation of temperature, load and sliding speed. In the vehicle test, a set of experiments were conducted in different conditions of track slopes and brake pressures seeking to emphasize the creep groan noise occurrences. Several materials were tested and a good correlation between tribometer results and vehicle results was achieved.