Design, Fabrication, and Testing of Stiffened Composite Panels with Acoustically Tailored Stiffeners

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Carbon fiber reinforced epoxy composites are being increasingly used for load bearing structural elements in large transport rotorcraft. However, due to the increased stiffness-to-density ratio of composites, problems associated with vibration and interior noise can be exacerbated by the use of composites in airframes. The current investigation explores the potential of optimized composite meta-structures to reduce vibration and interior noise in rotorcraft. The approach involves designing a taper into the thickness of blade stiffeners which, when combined with a limited amount of absorbing material in the thinned region, creates what is known as an “acoustic black hole” (ABH) in the stiffener. It is hypothesized that optimally designed ABH stiffeners can reduce broadband vibrations in stiffened panels. An optimization routine has been developed to determine the tradeoffs between vibration, mass, and buckling load due to compression parallel to the stiffeners. The tradeoffs are visualized using a 3-D Pareto front that helps the designer decide on the optimal design. Carbon/epoxy panels were made using vacuum-bag-oven processing with out-of-autoclave prepreg and verified to be of good quality. Panel vibration, buckling onset, and post-buckling load-deflection behavior were simulated using finite elements and measured using model testing and compression testing. Based on preliminary results, ABH-tapered stiffened panels have the ability to reduce radiated noise without a significant penalty in the mass and compressive load-bearing capability.

Original languageEnglish (US)
Title of host publicationFORUM 2023 - Vertical Flight Society 79th Annual Forum and Technology Display
PublisherVertical Flight Society
ISBN (Electronic)9781713874799
StatePublished - 2023
Event79th Vertical Flight Society Annual Forum and Technology Display, FORUM 2023 - West Palm Beach, United States
Duration: May 16 2023May 18 2023

Publication series

NameFORUM 2023 - Vertical Flight Society 79th Annual Forum and Technology Display

Conference

Conference79th Vertical Flight Society Annual Forum and Technology Display, FORUM 2023
Country/TerritoryUnited States
CityWest Palm Beach
Period5/16/235/18/23

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Control and Systems Engineering

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