Measurement of vibro-acoustic noise of drum brake under various contact conditions

Abstract

Drum brakes are vital safety components, widely used in automobiles due to their greater availability and quick replaceability compared to disc brakes. Since automobiles are used in all weather conditions, the braking performance also changes accordingly. Penetration of water, oil, and dust between the brake lining and the drum directly affects the contact parameters. These critical contact parameters (such as friction coefficient, contact damping, and stiffness) in turn affect the dynamic and acoustic responses of the nonlinear system. In this paper, the variation in the vibro-acoustic characteristics of a drum brake due to the presence of water, oil, and dust on the brake lining is studied experimentally by measuring the radiated acoustic signals and the system response. The braking performance under different conditions is quantified based on the system response while the acoustic behaviour of the system is studied using the acoustic measurements. This study would help in determining the safety of the automobile even under such abnormal braking conditions. Further, the acoustic measurements can be used to assess the contact condition of the braking system. It is envisaged to develop an improved health monitoring system for drum brakes.