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)

Personal Author(s) : Nederveen,A. ; de Rijk,P. ; Broek,D. ; Schijve,J.

Report Date : 31 JAN 1964

Pagination or Media Count : 30

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)

Descriptors :   (*WINGS, LOADS(FORCES)), (*FATIGUE(MECHANICS), WINGS), TESTS, TEST EQUIPMENT, VISUAL INSPECTION, FRACTURE(MECHANICS), X RAYS, NETHERLANDS, TRANSPORT AIRCRAFT

Subject Categories : Transport Aircraft
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE