Accession Number:

AD0631572

Title:

EXPERIMENTAL DETAILS OF TESTING A FULL-SCALE STRUCTURE WITH RANDOM AND PROGRAMMED FATIGUE LOAD SEQUENCES.

Descriptive Note:

Scientific rept.,

Corporate Author:

NATIONAL AERO- AND ASTRONAUTICAL RESEARCH INST AMSTERDAM (NETHERLANDS)

Report Date:

1964-01-31

Pagination or Media Count:

30.0

Abstract:

For an investigation on the equivalence of random and programmed fatigue loads, eight full-scale wing center sections were tested. The report describes the fatigue machine developed for this purpose and some testing experience. Load monitoring of the hydraulic machine occurs by comparing a feed-back signal from a load cell with the output of a selected Wheatstone circuit with an adjustable potentiometer. There are 32 circuits which can be selected by a digital tape reader in any arbitrary sequence. In this way a random sequence of 32 load levels can be applied. The hydraulic and the electronic parts are described in some detail. In eight fatigue tests a good reliability and accuracy were obtained. During the fatigue tests the inspections for cracks were made visually and with X-ray equipment. Visual inspections were made when the test was running, in view of the increased sensitivity. The results of the X-ray method for small cracks were very sensitive for the mean load in the structure. Useful results were obtained. Author

Subject Categories:

  • Transport Aircraft
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE