Accession Number:

ADA426345

Title:

Fatigue Crack Growth in Several 7050T7451 Aluminium Alloy Thick Section Plates with Aircraft Manufacturer's and Laboratory Surface Finishes Representing Some Regions of the F/A-18 Structure

Descriptive Note:

Technical rept.

Corporate Author:

DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV

Personal Author(s):

Report Date:

2003-12-01

Pagination or Media Count:

84.0

Abstract:

This is the third in a series of papers that examine material factors likely to influence the fatigue life of FA-18 structures. Work leading up to these papers has highlighted a number of concerns about the fatigue variability of the 7050 aluminium alloy thick section plate and the effect that the surface condition of finished components has on service fatigue crack initiation and life. This report examines a series of fatigue test specimens that were cut from three different 7050 plates, including two aircraft manufacturers plates. Following the tests, quantitative fractography was used to produce crack growth curves for each fatigue specimen, allowing a detailed interpretation of the crack growth to be made, including a measure of the severity of the flaws from which the main fatigue cracks initiated. Comparisons between previously tested 7050 plate, and the three plates tested here were made, with the finding that the crack growth rates and the flaws from which the cracking initiated were very similar to those previously examined. 45 tables, 48 figures, 24 refs.

Subject Categories:

  • Attack and Fighter Aircraft
  • Coatings, Colorants and Finishes
  • Metallurgy and Metallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE