Dynamic Vibration Absorber for Squeal Noise Suppression in Simple Model Structures

In recent research it was found that squeal noise caused by friction-induced vibration can result in mode coupling instability. Presently, there is no method that can be reliably used to eliminate this kind of noise. This paper is focused on the use of dynamic vibration absorbers (DVAs) to suppress the generation of squeal noise. The performance of the DVA is investigated numerically for two simple cases, i.e. a simple two-degree of freedom model, and an L-shape space frame. It is found that the DVA can be applied to shifting or reducing the unstable region of mode coupling, by which the unstable region is removed from the operating condition. Particularly, the addition of the DVA in horizontal direction on the near-point-of-friction can possibly avoid unstable mode coupling. However, the addition in vertical direction will increase the possibility of squeal noise incident. Moreover, a high frequency DVA in horizontal direction at the near-point-of-friction shifts the unstable region into higher normal contact stiffness and higher friction coefficient. Consequently, addition of a mass with very stiff spring or a rigid mass in the horizontal direction can prevent the occurrence of unstable mode coupling, as long as it is not coupled with the vertical direction. If the added mass affects the dynamic behaviors in both vertical and horizontal directions, squeal noise in the original normal contact stiffness can still occur.