Acoustic radiation damping of flat rectangular plates subjected to subsonic flows. Part II: Composite

The acoustic radiation damping for various laminated composite and aluminum plates subjected to a uniform, subsonic, and steady flow has been predicted. The predictions are based on the linear equations of motion of a flat plate. The fluid loading is characterized as the perturbation pressure derived from the linearized Bernoulli and continuity equations of fluid mechanics. Parameters varied in the analysis include Mach number and plate material properties and ply lay-up. Results show that the fluid loading can significantly affect realistic plate responses. Universal curves are presented where the acoustic radiation damping normalized by the mass ratio is a smooth function of the reduced frequency. A separate curve was required for each Mach number and plate aspect ratio. Generally, graphite/epoxy and carbon/carbon plates have higher acoustic radiation damping values than similar aluminum plates, except near plate divergence conditions resulting from aeroelastic instability. In addition, acoustic radiation damping values can be greater than or equal to the structural damping ratio component (assumed as 0·01) for the higher Mach numbers. © 1994 Academic Press Ltd.

Duke Scholars

Author Earl H. Dowell Thomas Lord Department of Mechanical Engineering and Materia ...