A cylindrical test-bed has been designed and modeled to aid in the study and control of interior acoustics in aircraft. The test-bed accounts for local as well as global structural-acoustic dynamics encountered in typical aircraft. The design is based on several existing aircraft and models used to study aircraft dynamics. The test-bed incorporates the basic geometry and materials common to a majority of aircraft, including an aluminum skin shrouding a framed structure composed of ribs and stringers. The design is approximately a one-third scale representation with a cylindrical geometry measuring 0.91 m diameter and 1.98 m long.The test-bed has been modeled using finite element methods and Rayleigh-Ritz assumed modes analysis. The models were used to refine the design of the test-bed as well as to model the coupled strucmral-acoustic dynamics. The models predict that the test-bed will have a modal structure commensurate with experimental identifications on existing aircraft.

Alternatives to honeycomb and corrugated core sandwich designs are explored to provide inexpensive and comparable performing sub-laminates that can be easily manufactured into more complex shapes. The core designs utilize two-dimensionally curved1 panels that can be manufactured using common manufacturing methods such as rolling, thermoforming, and stamping. The panels are designed using mathematical formulas and algorithms to provide quasi-isotropic behavior in bending. Experimental results indicate that these designs can provide comparable performance to honeycomb core laminates.