Map of low-frequency stick–slip of a creep groan

Abstract

A map that shows the necessary condition for avoiding the generation of low-frequency stick–slip of a creep groan is introduced. The map is obtained as a result of comprehensive investigation employing a novel caliper–slider experimental model. According to the map, creep groan generation is controlled by two dimensionless parameters, designated as stiffness ratio, Sr, and low-frequency stick–slip index, Ls. Stiffness ratio, Sr, is the ratio of structure stiffness to the stiffness at contact interface and Ls is an index formed by various parameters such as normal force, sliding velocity, and difference between static and kinetic coefficients of friction. On the experimental model, creep groan generation can be avoided if one or both of the following conditions is fulfilled: (a) stiffness ratio, Sr, larger than 40 (Sr>40) and/or (b) low-frequency stick–slip, Ls, index larger than 400 (Ls index>400). It is expected that the map can be used as a useful guideline for avoiding the generation of similar phenomenon on a real brake system.