Title: Brake squeal analysis by finite elements

Authors: Wayne V. Nack

Addresses: General Motors Corporation, 30200 Mound Road, 480-111-N26, Warren, MI 48073, USA

Abstract: An approximate analysis method for brake squeal is presented. Using MSC/NASTRAN, a geometric nonlinear solution is run using a friction stiffness matrix to model the contact between the pad and rotor. The friction coefficient can be pressure dependent. Next, linearised complex modes are found where the interface is set in a slip condition. Since the entire interface is set sliding, it produces the maximum friction work possible during the vibration. It is a conservative measure for stability evaluation. An averaged friction coefficient is measured and used during squeal. Dynamically unstable modes are found during squeal. They are due to friction coupling of neighbouring modes. When these modes are decoupled, they are stabilised and squeal is eliminated. Good correlation with experimental results is shown. It will be shown that the complex modes base-line solution is insensitive to the type of variations in pressure and velocity that occur in a test schedule. This is due to the conservative nature of the approximation. Convective mass effects have not been included.

Keywords: brake squeal; dynamic instabilities.

DOI: 10.1504/IJVD.2000.001895

International Journal of Vehicle Design, 2000 Vol.23 No.3/4, pp.263-275

Available online: 18 Aug 2003 *

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