Title: Measurement of the dynamic centre of pressure of the disk/pad interface during a braking operation

Authors: John D. Fieldhouse, Naveed Ashraf, Chris Talbot, Thierry Pasquet

Addresses: School of Computing and Engineering, The University of Huddersfield, Queensgate, Huddersfield, Yorkshire, HD1 3DH, UK. ' School of Computing and Engineering, The University of Huddersfield, Queensgate, Huddersfield, Yorkshire, HD1 3DH, UK. ' School of Computing and Engineering, The University of Huddersfield, Queensgate, Huddersfield, Yorkshire, HD1 3DH, UK. ' Robert Bosch France SAS, Chassis Systems Brake – Etablissement de Drancy CB/ENV, 126, rue de Stalingrad – 93700 Drancy, France

Abstract: This paper demonstrates the influence of the trailing end of the piston, or inboard, pad on the propensity of a brake to generate audible squeal. The unique technique was employed to measure the dynamic CoP at the pad/disk interface during a normal braking operation. This novel technique uses an embedded pressure sensitive film within the pad. The paper also presents the co-planar analysis of the pad/caliper contact regions and its influence on the position of the disk/pad CoP. The analysis shows how the trailing end of the piston pad influences the position of the CoP and goes on to explain why the centre moves as the pad abutment vibrates against the abutment. The paper includes additional work with a 12-piston opposed caliper where the initial CoP may be varied both along the pad and radially. Results show a very definite movement of the CoP as the brake pressure is increased.

Keywords: disk brake squeal; disk brakes; brake pads; CoP; centre of pressure; vehicle braking; vehicle design; pressure sensitive films; brake pressure.

DOI: 10.1504/IJVD.2009.027116

International Journal of Vehicle Design, 2009 Vol.51 No.1/2, pp.73 - 104

Published online: 15 Jul 2009 *

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