Instabilities Arising From the Frictional Interaction of a Pin-Disk System Resulting in Noise Generation

Abstract

A steel pin, supported on a flexible cantilever, is pressed against a thin steel disk which rotates at a uniform angular speed. The orientation of the pin’s central axis to the plane of the disk, the bending and torsional stiffnesses of the pin support, the stiffness of the disk, and the line of action of the resultant interactive force are all shown to affect the self-induced coupled frequencies and modes generated. The analysis of the experimental arrangement in terms of a three-degree-of-freedom pin subsystem and a single-degree-of-freedom disk element suggests that the system is unstable for certain combinations of the variables. The instabilities are shown to belong to a class of “geometrically induced” or “kinematic constraint” instability. The region of squeal-noise generation within the experimental rig is shown to correspond to the oscillatory unstable region predicted theoretically. The noise generated is similar to disk-brake squeal, and so the work furthers the understanding of this practical problem.

Effects of damping on brake squeal coalescence patterns – application on a finite element model

“…The real and imaginary parts of the complex eigenvalues are respectively responsible for the stability and for the frequency of the corresponding modes. This technique has been used on lumped models first(see for example [1], [2], [3], [4], [5], [6]). Then, thanks to an increase in computer capabilities, it has been extended to finite element (FE ) models.…”

Investigation of the relationship between damping and mode-coupling patterns in case of brake squeal

“…The real and imaginary parts of the complex eigenvalues are respectively responsible for the stability and for the frequency of the corresponding modes. This method was first used on lumped models [1,[4][5][6][7][8]. Then, improvements in computer systems have made it possible to perform analyses on finite element (FE) models [9].…”

Finite element analysis on squeal-noise in railway applications

“…In this paper, we chose to keep constant the friction coefficient µ, since it is possible to obtain variables friction forces due to the presence of variables closing forces. This is the assumption underlying the studies carried out by Spurr [71], Earles and Soar [72,73]. In this paper, we show that if two modes are geometrically coupled, for increasing values of friction coefficient, frequencies tend to coincide [74][75].…”