Adaptive Structural Mechanics for Acoustic Application

Abstract

This paper demonstrates the enormous potentials of adaptive structural systems to realize active noise control. It explains both the principle ideas of active noise control as well as the technology of adaptive structures. After a review of acoustic fundamentals and typical acoustic problems some approaches are given from the adaptive structures technology for cars, rockets, satellites, form measuring machines, ducts and high speed trains. Helicopters are primary examples for two-way coupling effects of structural vibrations and noise. Therefore, two more detailed chapters are directed to adaptive helicopter blades for active suppressions of blade-vortex-interaction effects and to carbon fibre reinforced thin plates with embedded piezoceramics for active acoustic impedance control. Diverse concepts and results of numerical studies are presented.