Fatigue tests with random and programmed load sequences with and without ground-to-air cycles: A comparative study on full-scale wing center sections

Fatigue tests were carried out on full-scale tension skins of a wing center section of 7075-T6 material. Variable-amplitude tests were carried out with the following load sequences: (a) random load, (b) program load, (c) random load with GTAC (ground-to-air cycles) and (d) program load with GTAC. Constant-amplitude tests were carried out with...

Experimental details of testing a full-scale structure with random and programmed fatigue load sequences

The effect of heat treatment on the propagation of fatigue cracks in light alloy sheet material

The effect was studied of artificial aging (up to and beyond maximum hardness, both with and without prior solution heat treatment) on the crack propagation in 2024-T3 alclad sheet. All heat treatments caused a noticeable increase of the rate of crack propagation, which was correlated with a decrease of ductility. The correlation is discussed...

The influence of the mean stress on the propagation of fatigue cracks in aluminium alloy sheet

Crack propagation : the results of a test programme based on a gust spectrum with variable amplitude loading

This paper deals with crack propagation under programme-fatigue loading; the programme being derived from a gust spectrum. The validity of the Palmgren-Miner rule for crack propagation has been studied and its usefulness for design purposes is discussed.

Fatigue tests on aluminium alloy lugs with special reference to fretting

Fatigue tests have been carried out on light alloy lugs of 2024 and 7075 material in order to investigate the effects of some geometrical parameters (lug size, geometry of lug) and various means to reduce fretting, viz. lubrication of the pin, flattened pins, slotted holes and expanded holes. Complete S-N curves have been determined at a...