Review of Damage Tolerance for Composite Sandwich Airframe Structures

Details

• Creators:
  Tomblin, J. ; Lacy, T. ; Smith, B. ; Hooper, S. ; Vizzini, A. ; Lee, S.
• Corporate Creators:
  Wichita State University ; University of Maryland (College Park, Md.)
• Corporate Contributors:
  United States. Department of Transportation. Federal Aviation Administration. Office of Aviation Research
• Subject/TRT Terms:
  • Composite construction
  • Sandwich construction
  • Engineering tolerances
  • Literature reviews
  • Standards
• Publication/ Report Number:
  DOT/FAA/AR-99/49
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report
• Corporate Publisher:
  United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center
• Description:
  The use of composite sandwich construction is rapidly increasing in current and future airframe designs especially for general aviation aircraft and rotorcraft. Typically, sandwich constructions for these applications use thin-gage composite face sheets (0.020" to 0.045") which are co-cured to honeycomb and foam cores. Due to the nature of these structures, damage tolerance is more complex than conventional laminated structures. Besides typical damage concerns such as through penetration and delamination, additional modes including core crushing and face sheet debonding must also be addressed. This complicates the certification process by introducing undefined Allowable Damage Limits (ADL) and Critical Damage Thresholds (CDT) as related to the ultimate and limit load carrying capability of the structure. This document provides a background review of previous damage tolerance investigations including an overview of traditional metallic damage tolerance methodologies. Illustrative summaries are presented which show the scope of previous investigation parameters such as impact energy, face sheet thickness, and core thickness of typical sandwich constructions. Also included is a compilation of damage tolerance certification procedures and regulations taken from FAR Part 23-29 for composite damage tolerance as well as recommendations from associated Advisory Circulars. Past and current airframe industry sandwich constructions which show the scope of current and future sandwich designs were also surveyed. In conclusion, a proposed future research approach and its methodology are presented which should aid in establishing certification guidelines and confidence involving the damage tolerance of sandwich constructions as they apply to general aviation aircraft and rotorcraft.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93702/dot_93702_DS1.pdf
• File Type:
  [PDF - 1.48 MB]
• Collection(s):
  FAA William J. Hughes Technical Center for Advanced Aerospace
• Main Document Checksum:
  urn:sha-512:915c6f5f6d06b7bca8aa2c7a91e7f855a89cad6424b0dc74ea2fbb2d516795a96ace0174438c24c3c47b7c057b63f5dd10db4981b5f651470681c0434f837f61