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Plasto-Elastic Stress Distributions in Lugs

Published online by Cambridge University Press:  07 June 2016

H. Fessler  and
D. J. Haines
H. Fessler
Affiliation:
The University of Nottingham
D. J. Haines
Affiliation:
The University of Nottingham
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Extract

A photoelastic layer was bonded to the face of aluminium alloy lugs and the strain distribution in the lugs was determined from the photoelastic fringe patterns which were recorded in a reflection-type polariscope. The semicircularly- ended lugs were loaded through neat fitting hardened steel pins. Assuming the maximum shear stress criterion of yield, the region of yielding under different loads was determined from the fringe patterns. Yield contours are shown for each of the four ratios of (hole diameter)/(lug width) tested. The greatest shear strains in the lugs were related to the applied loads. The extent of yield across the section normal to the direction of loading was measured for different loads and it was found that the progress of yield across this section is independent of the (hole diameter)/(lug width) ratio. The residual stresses on this section were also estimated. Complete yielding across the lug was related to the properties of the material and to the fracture strength of the lugs. Local yielding due to surface irregularities remained local, showing that “bedding in” does not weaken the component under static loading conditions.

Type
Research Article
Information
Aeronautical Quarterly , Volume 10 , Issue 3 , August 1959 , pp. 230 - 246
Copyright
Copyright © Royal Aeronautical Society. 1959

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