Bonded Repair of Corrosion Grind-Outs

Abstract

The U.S. Air Force is operating a large fleet of aging aircraft. Some examples of problems that aging aircraft can encounter are fatigue and corrosion. This research focuses on bonded repair of exfoliation corrosion in the upper wing skin of the E-8C Joint Star (B7O7) military transport aircraft. Upper wing skins on the E-8C have shown extensive exfoliation damage. According to Boeing, structural integrity could be compromised by further corrosion and fatigue cracking in case this damaged material is not removed. Therefore, the current approach to deal with this damage is to remove the exfoliated material by grinding it out, after which the removed material is not replaced. Depending on the location on the wing, local grind-outs are allowed, up to 25% of the skin thickness. However, if the exfoliation extends beyond this limit, this approach is no longer allowed since too much material is lost. An internal repair or wing plank replacement are the only repairs currently permitted by the Structural Repair Manual (SRM). Both repair options are very costly. The purpose of the current research is to develop a flush bonded repair method that restores structural integrity to corrosion grind-outs deeper than 25% of the skin thickness, so that severe corrosion cases can be handled without costly repair.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2005
Accession Number
ADA437177

Entities

People

  • Stephan Verhoeven

Organizations

  • United States Air Force Academy

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Aircrafts
  • Aluminum
  • Amplitude
  • Corrosion
  • Crack Tips
  • Cracks
  • Delamination
  • Engineering
  • Failure Mode And Effect Analysis
  • Fatigue Tests (Mechanics)
  • Materials
  • Mechanics
  • Modulus Of Elasticity
  • Residual Stress
  • Stresses
  • Tensile Strength

Readers

  • Facility/Structural Engineering.
  • Materials Science and Engineering.
  • Systems Analysis and Design