Accession Number:

AD0631574

Title:

FATIGUE LIVES OBTAINED IN RANDOM AND PROGRAM TESTS ON FULL-SCALE WING CENTER SECTIONS.

Descriptive Note:

Scientific rept.,

Corporate Author:

NATIONAL AERO- AND ASTRONAUTICAL RESEARCH INST AMSTERDAM (NETHERLANDS)

Personal Author(s):

Report Date:

1963-12-15

Pagination or Media Count:

48.0

Abstract:

Fatigue tests were conducted on eight full-scale wing center sections of the F-27 Friendship aircraft. The specimen consisted of the tension skin, including all stiffening elements. The remainder of the wing was replaced by a dummy structure. Two tests were carried out for each of the following load sequences 1 random load 2 programmed load 3 random load with ground-to -air cycles 4 programmed load including ground-to-air cycles. The random loading was based on a simulation of strain gage records obtained by flying in turbulent air. The primary aim of the investigation was to study the equivalence of random and programmed loadings. A comparison of the fatigue lives and the critical components indicated the following trends a Cracks were found in the same components for all tests. b The fatigue life under the programmed load was slightly longer than in the random load tests, both for tests without and with ground-to-air cycles. c The addition of ground-to-air cycles reduced the fatigue life to 50 or even less. For one fatigue-sensitive element sufficient data were available for a statistical evaluation this indicated that the scatter within one structure may be smaller than the variability between a number of identical structures. Author

Subject Categories:

  • Transport Aircraft
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE