Accession Number:

ADA159676

Title:

Effectiveness of Fatigue Life Enhancing Fasteners in the Design and Rework of Aircraft Structures

Descriptive Note:

Final rept. Feb 1982-Feb 1985

Corporate Author:

NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AIRCRAFT AND CREW SYSTEMS TECHNOLOGY DIRECTORATE

Personal Author(s):

Report Date:

1985-02-28

Pagination or Media Count:

34.0

Abstract:

Fatigue life data were obtained for four different types of fatigue life enhancing FLE fasteners installed in new uncracked holes and in reworked, pre-cracked holes. The first condition represented a new design where the FLE fasteners are installed during production. The second condition represented a structural rework in which fastener holes are reamed to a larger size to remove fatigue or fretting damage but might still contain a small undetected crack. Results showed that the FLE fasteners produced approximately the same overall fatigue life in the new design and the rework condition and provided a significant increase in life compared to conventional non-FLE fasteners. Tests were performed with 7075-T6 aluminum alloy under spectrum loading typical of a Navy fighterattack type of aircraft. For the rework condition, the pre-crack size was limited to .03 inch .76mm. Flush head fasteners were used in all tests. Keywords Crack-growth Fasteners Structural rework Joints.

Subject Categories:

  • Aircraft
  • Couplers, Fasteners and Joints
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE