The first part of this thesis work deals with a literature review of the brake squeal phenomenon, ranging from the early analytic models up to the most recent numerical approaches. Then, it is presented the Brake POD (Pad On Disc), a new concept of test bench designed by Brembo that is devoted to brake squeal investigation. The principal components of the system are characterized by means of different experimental approaches, as FRFs and laser vibrometries. Then, a simplified numerical model is proposed to investigate the possible squealing frequencies by means of CEA (Complex Eigenvalue Analysis) in two different configurations of the test bench. The experimental investigation of brake squeal is performed with a DOE (Design Of Experiments) approach on a dyno bench, varying the system parameters on different levels. The results are analysed and compared to that of the numerical analyses. Then, a new numerical model is proposed and several sensitivity analyses are performed to evaluate the system robustness and the correlation level, the outcomes are compared to the experimental squealing frequencies. Finally, the pads kinematic is experimentally investigated in different working conditions. In the end, the results are compared and summarized, proposing future development of the activity.
La parte iniziale di questo lavoro è dedicata a presentare una revisione degli articoli presenti in letteratura riguardanti il fenomeno del brake squeal, a partire dai primi modelli analitici fino ad arrivare ai più recenti approcci con codici ad elementi finiti. Successivamente viene presentato il Brake POD (Pad On Disc), un nuovo concetto di banco prova progettato da Brembo per studiare nel dettaglio i fenomeni legati al brake squeal. I componenti principali del sistema sono caratterizzati attraverso differenti approcci sperimentali, come FRF e vibrometrie laser. In seguito, un modello numerico semplificato del sistema viene proposto per valutarne le possibili frequenze di squeal attraverso il calcolo CEA (Complex Eigenvalue Analysis) in due differenti configurazioni. Lo studio sperimentale dei fenomeni di brake squeal viene eseguito con un approccio DOE (Design of Experiments) su banco dinamico, variando i parametri del sistema su differenti livelli. I risultati ottenuti vengono analizzati e comparati a quelli numerici. Quindi, un nuovo modello numerico viene proposto e su di esso vengono svolte differenti analisi di sensitività per valutare la robustezza del sistema e il suo livello di correlazione; i risultati vengono comparati con le frequenze di squeal ottenute sperimentalmente. Nell'ultima attività svolta, la cinematica delle pastiglie viene studiata con un approccio sperimentale in differenti condizioni operative. Infine, i risultati delle differenti analisi sperimentali e numeriche vengono sintetizzati e comparati, proponendo sviluppi futuri per l’attività.
Numerical and experimental influence analysis of the brake caliper functional features over brake squeal phenomena
PAGNONI, MICHELE
2017/2018
Abstract
The first part of this thesis work deals with a literature review of the brake squeal phenomenon, ranging from the early analytic models up to the most recent numerical approaches. Then, it is presented the Brake POD (Pad On Disc), a new concept of test bench designed by Brembo that is devoted to brake squeal investigation. The principal components of the system are characterized by means of different experimental approaches, as FRFs and laser vibrometries. Then, a simplified numerical model is proposed to investigate the possible squealing frequencies by means of CEA (Complex Eigenvalue Analysis) in two different configurations of the test bench. The experimental investigation of brake squeal is performed with a DOE (Design Of Experiments) approach on a dyno bench, varying the system parameters on different levels. The results are analysed and compared to that of the numerical analyses. Then, a new numerical model is proposed and several sensitivity analyses are performed to evaluate the system robustness and the correlation level, the outcomes are compared to the experimental squealing frequencies. Finally, the pads kinematic is experimentally investigated in different working conditions. In the end, the results are compared and summarized, proposing future development of the activity.| File | Dimensione | Formato | |
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2018_10_Pagnoni.pdf
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https://hdl.handle.net/10589/142825