Advanced damping system for broadband vibration and interior noise control of composite airframes of transport rotorcraft

The object of the proposed research is todetermine the trade-off in the stiffening, mass and damping performance of an ABH-stiffenedcomposite panel. The stiffener cross-section will be an ABH shape with damping elements nearthe tip with the design parameters determined using formal, multi-objective optimization.Additionally, a combined active/passive damping system will be investigated to achieve the bestbroadband reduction of the meta-structure. The resulting effort is expected to provide thefollowing advancements: develop a novel stiffening concept for lightweight, quiet compositeairframes using acoustic black hole (ABH) technology, develop novel structural-acousticoptimization method to guide design and establish trade-offs for stiffened panels featuring ABHstiffeners and passive / shunt circuit damping, Fabricate and test an ABH meta-structure to validatethe new concepts and analysis methods. Educate students and prepare them for DoD careersfocused on advanced aviation structures technologies. A basic design for an ABH-stiffened panelwill be developed. The skin will be a thin composite and