Abstract: When a vehicle is negotiating a tight curve, high frequency squeal noise can be generated, which is attributed to the negative damping effect introduced by the negative slope of friction creepage curve, i.e. negative damping theory. However, some research found that when the negative slope is eliminated, squeal noise still can be generated. To solve this problem, a two degree of freedom coupled dynamics model was developed based on both mode coupling and negative damping theory, and the effects of key parameters on the stability of the system are analyzed using the complex eigenvalue method. The results show that the system is unstable and the squeal noise tends to be excited when some key parameters are in certain ranges. As the generation and sound pressure level of squeal noise is subject to the initial conditions, it is necessary to analyze the chaotic dynamics of the system. The analysis results of chaotic behavior can illustrate the evolution process of system from steady state to quasi-periodic behavior and then to chaotic behavior. Furthermore, the parameter range in which the vibration behavior of system is more susceptible can be determined. The torsional vibration is further included in this model to analyze the effect of torsional vibration on the system vibration. The analysis results illustrate the effect of torsional vibration on the system vibration in the combined parameters, providing a theoretical basis and analysis method for the effective prediction and mitigation of squeal noise.

Key words: squeal noise, mode coupling, stability analysis, chaotic behavior, torsional vibration