Structural modifications for squeal noise reduction: numerical and experimental validation

Squeal is an example of noise caused by vibrations induced by friction forces that lead to dynamic instability of the brake system. Several experimental, theoretical and numerical works have been carried out over the last six decades. Certain of these works have focused on simplified brake systems and identified ‘lock-in’ instability as being the cause of squeal. This paper presents a short bibliography of previous works and the most recent application of research developed using a simplified brake system called TriboBrake. Commercial brake design is not capable of avoiding modal coupling due to ‘lock-in’ sensitivity to system dynamics, high modal density and uncertainties regarding the natural frequencies. This paper suggests an innovative approach for avoiding the growth of squeal vibrations, by making lumped structural modifications to the rotor. Experimental and numerical results are presented. Biographical notes: Francesco Massi received his PhD degree from the Faculty of Mechanical Engineering of the University of Rome “La Sapienza” and from the doctoral school, MEGA at INSA, Lyon, in 2006. In 2007 he obtained the position of Maitre de Conferences at the Laboratory of Contact and Structural Mechanics, INSA Lyon. His research activities focus on applied mechanics with emphasis given to vibrations, acoustics and tribological problems. His major topics are friction-induced vibrations, induced wear of contact surfaces under vibration, and the interaction between system dynamics and local behaviour at contact surfaces. Biographical notes: Laurent Baillet received his PhD degrees from the doctoral school MEGA of the INSA of Lyon in 1994. Since 2005 he is Professor at the Joseph Fourier University. He is leader of the landslides team in the Laboratory of Geophysics and Tectonophysics. His areas of research include finite element formulation in large deformation frictional contact problem, dynamic rupture in frictional interface, rock-fall avalanche. in su -0 03 55 11 0, v er si on 1 22 J an 2 00 9 Author manuscript, published in "International Journal of Vehicle Design 51, 1-2 (2009) 168-189" DOI : 10.1504/IJVD.2009.027120