A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes

Abstract

This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes

Numerical and experimental diagnosis of complex rotor system by time-frequency techniques

“…These can be easily distinguished near the first critical speed. This inference concurs with the results in [18].…”

Numerical study of friction-induced instability and acoustic radiation – Effect of ramp loading on the squeal propensity for a simplified brake model

“…The nonlinear time analysis shows that the displacement profile is modified and the spectrum analysis highlights the appearance of new harmonic components. This fact was also illustrated in [13]: the authors propose a global strategy based on experiments and transient simulations for squeal understanding and characterization on industrial railway brakes. This study showed that the nonlinear transient vibrations may induce the appearance of new resonance peaks and so that the stability is not sufficient to predict squeal noise.…”

“…This analysis highlights the fact that the time dependent loading plays a significant role in squeal initiation in addition to nonlinear effects. Influence of the ramp loading for the single instability cases: case 2 static against cases 2 slow ramp and 2 fast ramp The time response of the case 2 static is calculated with the static loading and the initial conditions defined by Equation 13. The system leaves the initial condition and self-excited vibrations are generated as indicated in Figure 5 (c).…”

“…Chevillot et al [12] provide simulations and experiments of a nonlinear aircraft braking system and show that the stability of the numerical model is efficient to experimentally reproduce squeal instability. For the parameters corresponding to potential squeal, the next step corresponds to nonlinear time analysis that is conducted to calculate the friction-induced vibrations [13]. Finally, the acoustic response is estimated with the multifrequency acoustic calculation method as explained in [14].…”

Shape optimization of a disc-pad system under squeal noise criteria

“…Understanding squeal noise requires the analysis of brake systems from a "vibration and acoustics" point of view. Though the generation of squeal noise is considered to be a very complex phenomenon with many mathematical models defining in their respective sense, one of the most common methods which is efficiently used in prediction is using the complex eigenvalue analysis, even if it is well known that it can lead to under or over-estimation of unstable modes [10,15,17]. The main advantage of this method remains its speed, especially in the context of optimization, where the objective functions have to be evaluated several times.…”