Dominant damping effects in friction brake noise, vibration and harshness: the relevance of joints

Abstract

Abstract:The experimental analysis of a single component of a brake system and an assembly consisting of three components is used to clarify the relevance of joints in terms of damping and nonlinearity in state-of-the-art brake systems. For this purpose a series of experimental modal analyses is conducted. A comparison of the results obtained from the single component and of the assembly strongly indicate that the joints which necessarily exist in an assembled structure have an impact on the dynamic behaviour of the structure. The modal damping values of the jointed structure are up to factor sixty higher than those of the single component values. Also, a significant amplitude dependency of the frequency response functions is visible. These observations demonstrate that joints are a major source of energy dissipation in friction brake systems and, in addition, that they introduce nonlinear behaviour to the system which has the potential to limit squeal amplitudes. Therefore, mechanical joints in brake systems should be considered as decisive design elements for noise-vibrationharshness (NVH) issues in brakes.http://mc.manuscriptcentral.com/jauto 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 F o r P e e r R e v i e w brake systems and, in addition, that they introduce nonlinear behaviour to the system which has the potential to limit squeal amplitudes. Therefore, mechanical joints in brake systems should be considered as decisive design elements for noise-vibration-harshness (NVH) issues in brakes.

Reconstruction of Governing Equations from Vibration Measurements for Geometrically Nonlinear Systems

“…It is superfluous to note that, in a sense, all real systems are nonlinear and may be described by linear models only within some restricted ranges of the governing parameters, or under particular conditions [9][10][11]. For example, almost all engineering applications are constituted by jointed structures [12][13][14][15][16] where frictional dissipation takes place [17,18]. Contact is mediated by roughness, which is well known to introduce nonlinear stiffening behavior [19][20][21][22].…”

The influence of joints on friction induced vibration in brake squeal

“…This aspect further motivates the choice of this method for the present work. Recent experimental studies suggest that there may be only very few dominant or relevant joints in friction brake systems [10]. An extension of the HB method to multi-instabilities in frictional excited systems can be found in [41].…”

“…There are definitely several possible sources of nonlinearity in brake systems which could determine finite amplitude vibration levels: nonlinear material characteristics of all components such as the lining material [9], the nonlinearity of the friction interface or the nonlinearity in the joints and contact interfaces of the system [10,11]. Interestingly, the latter has barely been looked at yet for the phenomenon of brake squeal even though the highly nonlinear behaviour of joints and contact interfaces is well known [12,13,14,15,16,17,18].…”

Squeaking friction phenomena in ceramic hip endoprosthesis: Modeling and experimental validation

“…Moreover, in vivo observations with patients, have suggested that squeaking seems to be generated mostly in those conditions [24]. Nevertheless, it should be kept in mind that joint damping can affect the squeaking behavior of the system [40] and further analysis on this point would be of interest. All the other contact interfaces have been defined as tie constraints [33].…”