How can automotive friction-induced noises be related to physical mechanisms?

2019

Nonlinear Dyn

The friction-induced vibration of a massslider with in-plane and transverse springs and dampers in sliding contact with a spinning elastic disc in three different situations of spinning speed, i.e. constant deceleration, constant acceleration and constant speed, is studied. The stick-slip motion in the circumferential direction and separation-re-contact behaviour in the transverse direction are considered, which make the system responses non-smooth. It is observed that the decelerating rotation of the disc can make the inplane stick-slip motion of the slider more complicated in comparison with constant disc rotation and thereby exerting significant influence on the transverse vibration of the disc, while the accelerating rotation of the disc contributes to the occurrence of separation during the vibration and thus influencing the vibration behaviour of the system. Numerical simulation results show that distinct dynamic behaviours can be observed in the three situations of spinning speed of disc and three kinds of particular characteristics of differences are revealed. The significant effects of decelerating and accelerating disc rotation on the friction-induced dynamics of the system underlie the necessity to consider the time-variant spinning speed of disc in the research of friction-induced vibration and noise.

Section: Introductionmentioning

confidence: 99%

Friction-induced vibration of a slider on an elastic disc spinning at variable speeds

Liu

2019

Nonlinear Dyn

“…Generally speaking, dry friction acts as a resistance to relative motion which dissipates energy of a system; however, under certain conditions, it can cause self-excited vibration in engineering as well as in daily life [1][2][3][4], and in most of these cases is undesirable. Examples include door hinges, squeaky chalk on a blackboard, data loss of a computer hard disc drive due to flutter of the disc and a most well-known noise problem, brake squeal [5][6][7] that happens in the brake system of an automobile.…”

Section: Introductionmentioning

confidence: 99%

“…Friction was also modelled as a follower force [14,18] or a moving load [19], or produced a friction couple [20][21][22]. Very recently, Elmaian et al [7] demonstrated through numerical simulation that three typical types of brake noise (that is, creak, squeal and squeak) could be generated by one dynamics model and which type of noise actually occurred depended on the contact state ratio.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Friction-Induced Vibration of a Slider–Belt System

Journal of Vibration and Acoustics

Guan

2016

A mass–spring–damper slider excited into vibration in a plane by a moving rigid belt through friction is a major paradigm of friction-induced vibration. This paradigm has two aspects that can be improved: (1) the contact stiffness at the slider–belt interface is often assumed to be linear and (2) this contact is usually assumed to be maintained during vibration (even when the vibration becomes unbounded at certain conditions). In this paper, a cubic contact spring is included; loss of contact (separation) at the slider–belt interface is allowed and importantly reattachment of the slider to the belt after separation is also considered. These two features make a more realistic model of friction-induced vibration and are shown to lead to very rich dynamic behavior even though a simple Coulomb friction law is used. Both complex eigenvalue analyses of the linearized system and transient analysis of the full nonlinear system are conducted. Eigenvalue analysis indicates that the nonlinear system can become unstable at increasing levels of the preload and the nonlinear stiffness, even if the corresponding linear part of the system is stable. However, they at a high enough level become stabilizing factors. Transient analysis shows that separation and reattachment could happen. Vibration can grow with the preload and vertical nonlinear stiffness when separation is considered, while this trend is different when separation is ignored. Finally, it is found that the vibration magnitudes of the model with separation are greater than the corresponding model without considering separation in certain conditions. Thus, ignoring the separation is unsafe.

“…The annoying noise can cause customers to doubt the quality of their automobiles. Friction-induced vibration has been generally accepted as the main reason for brake squeal [1][2][3][4]. Another consequence of friction-induced disc vibration is data losses of a computer hard disc drive because of its undesirable vibration.…”

Section: Introductionmentioning

confidence: 99%

Friction-induced vibration of an elastic disc and a moving slider with separation and reattachment

Guan

2016

Nonlinear Dyn

The transverse vibration of an elastic disc, excited by a preloaded mass-damper-spring slider dragged around on the disc surface at a constant rotating speed and undergoing in-plane stick-slip oscillation due to friction, is studied. As the vertical vibration of the slider grows at certain conditions, it can separate from the disc and then reattach to the disc. Numerical simulation results show that separation and reattachment between the slider and the disc could occur in a low speed range well below the critical disc speed in the context of a rotating load. Rich nonlinear dynamic behaviour is discovered. Time-frequency analysis reveals the time-varying properties of this system and the contributions of separation and in-plane stick-slip vibration to the system frequencies. One major finding is that ignoring separation, as is usually done, often leads to very different dynamic behaviour and possibly misleading results.