Study on automotive disc brake squeal using finite element analysis and design of experiments

Abstract

The motivation for the present work lies in the fact that the disc brake squeal depends on a large number of parameters. Hence, using traditional parametric studies by changing one factor at a time is not sufficient for evaluation the brake system. The need of a new approach to investigate the effects of combination of several factors on squeal generation and its interactions is very much required to help improve the design of brake components. In this thesis a new approach based on integrating finite element simulations, a preferred method to investigate the brake squeal, with design of experiments (DOE) technique which is widely used in many engineering fields is conducted. The first part of this work deals with an improved three dimensional FE model of the disc brake corner which includes the disc brake assembly and the steering knuckle assembly. Till now, FE model of brake corner is not considered in details by most researchers. The present study is considered the FE model of the brake corner and used more validation stages than have been used by other researchers. Stability analysis of the disc brake assembly with frequencies ranging from 1 kHz to 10 kHz is performed to predict unstable frequencies using complex eigenvalue analysis (CEA). This thesis presents a significant method for reducing disc brake squeal through structural modifications of brake components. Several types of materials for disc brake components as found in practice are simulated to reduce brake squeal. This research work also covers DOE approach to investigate the effects of several factors on squeal generation and its interactions to improve the design of brake components. The DOE results showed that non-linear model for real parts of the complex eigenvalue based on central composite design of experiments is successfully developed for prediction of brake squeal. Deviations between predicted and simulation results are found to be within ±15%. It shows reasonable agreement and also the adequacy of the developed model in prediction. newline newline