Investigation of ways to use smart materials in active reduction of noise emitted by vibrating elements of machines

The project embraces development and evaluation of a model of an active noise reduction (ANR) system. The developed model consists of the control unit, the electroacoustic subsystem, which serves as a primary source, auxiliary electronic circuits used for generation of various test signals and measurement and the actuator which serves as a secondary source. The primary source, which simulates a model of a vibrating element of a machine emitting noise, consists of a loudspeaker in a casing and a vibrating element attached to the casing just in font of a loudspeaker. An actuator of the ANR system is attached directly to the vibrating element of the primary source. The developed model of the ANR system was tested in laboratory conditions. During those tests its operation with various kinds of vibrating elements and secondary sources was analyzed. It was shown that if smart materials were used as actuators, it was possible to actively reduce the noise emitted by the vibrating elements of the model.As a result of the project a monograph on various aspects of the use of smart materials for active reduction of vibration and noise was prepared.