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Title: Modelling and simulation of disc brake contact analysis and squeal
Author: Bakar, Abd Rahim Abu.
ISNI:       0000 0001 3437 9328
Awarding Body: University of Liverpool
Current Institution: University of Liverpool
Date of Award: 2005
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This thesis proposes a new methodology of predicting squeal using the finite element method in which three validation stages are established. A detailed 3-dimensional finite element model of a real disc brake is not only validated through modal analysis at the components and assembly levels but also through contact analysis where static contact pressure distribution and its contact area match with the experimental results. The main key issue in this research is the refinement of contact interface model of the friction material. Having assumed a smooth and flat surface (or perfect contact interface) in the past, current research considers a real surface topography of which measurementsa re carried out in order to obtain a realistic contact interface model. It is found that with the refined disc brake model, a good correlation is achieved between the predicted results and experimental ones on the contact pressure distribution and contact area at the piston and finger pads. Complex eigenvalue analysis that is available in ABAQUS software package is used as the main tool to predict squeal generation. Prediction of squeal occurrence is limited to a frequency range of I kHz to 8 kHz. Simulations of disc brake squeal are performed at different friction characteristics with the inclusion of friction damping for the perfect contact interface and real contact interface models. It is shown that the real contact interface model predicts squeal occurrences much better than the perfect contact interface model by considering the effect of negative u-v slope and friction damping. Comparison between complex eigenvalue analysis and dynamic transient analysis using a reduced FE model is also made for different contact schemes. It is found that using small sliding with Lagrange multiplier contact scheme predicted results in both analyses in a good agreement. Wear effects on instability of the disc brake assembly are also simulated. The results show that with the inclusion of wear, unstable frequencies are predicted to appear and disappear as wear progresses even though similar boundary conditions and operating conditions are imposed to apparently the same disc brake model. This phenomenon may explain the fugitive nature of squeal behaviour.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available