Recent Advances in Vibro-Acoustics and Noise Control Of Aerospace Composite Structures

Abstract

Composite structures are widely used in a variety of industrial applications due to their excellent mechanical properties, such as high stiffness-to-weight ratio, etc. The same characteristics that impart excellent mechanical efficiency, however, also result in efficient transmission and radiation of acoustic noise, posing serious vibro-acoustical problems for a variety of engineering systems in which composite structures are used. The composite structures are efficient radiators of noise mainly due to excitation and propagation of supersonic bending and/or shear waves in the structures. Composite skin-stringer structures mostly support supersonic flexural or bending waves propagating in the laminated structure whereas noise radiation by sandwich structures is dominated by supersonic shear waves in the core. Noise control of composite structures presents a significant technical challenge as the main advantages afforded by these structures, such as low weight and high strength, must not be compromised by added treatments. Recently, research has also been conducted to improve attenuation of vibration and noise radiation from such structure using nano-technology. This paper presents state-of-the-art review of the vibro-acoustics and noise control technology for aerospace composite structures.