Discussions on Squeal Triggering Mechanisms – A Look beyond Structural Stability

This paper discusses friction excitations, and possible squeal triggering mechanisms and processes, such as stick-slip and chaos. Stick-slip and chaotic behavior associated with brake squeals are discussed, along with some measurement results and data analyses. Recurrence Quantification Analysis (RQA) and Visual Recurrence Analysis (VRA) software are introduced for analyzing chaotic events. Examples of “Phase Space Plot” of squeal data using VRA are also presented, demonstrating that squeal is neither random nor fully deterministic, but somewhere in between, i.e. chaotic – deterministic and patterned.