Analytical investigation of stick-slip motions in coupled brake-driveline systems

In this paper, we investigate the brake creep-groan problem by formulating the issues in terms of two dynamic sub-systems that are coupled at the friction interface, and thus, experience stick-slip motions. Thorough examination of the nature of discontinuous solutions using numerical methods is a useful prelude to analytical studies. We examine such dynamics through parametric studies for magnitude and rate of brake release, where the vehicle is initially at rest and under low constant drive torque. Dependency on the initial conditions and solution flow before reaching the orbit will thus be illustrated. Four types of motions (one steady sliding and three stick-slip) are found based on extensive studies. Our formulation and analysis should lead to a better understanding of the brake groan phenomenon and systems coupled by interfacial friction.