Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-07T12:18:56.086Z Has data issue: false hasContentIssue false
  • English
  • Français

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
Get access

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

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Howard, R. M. Strength Tests on Lugs in Sheet Materials. M.A.P. Scientific and Technical Memorandum No. 23/24, June 1945.Google Scholar
2. Baillie, I. L. G. Design of Lugs in Bar Materials. Bristol Aircraft Ltd., Admin. Note. No. 12, J.A.C. 418/303, November 1958.Google Scholar
3. Heywood, R. B. The Strength of Lugs in Fatigue. R.A.E. Technical Note Structures 182, January 1956.Google Scholar
4. Linge, J. R. Investigations into a Photoelastic Method for Direct Measurement of Surface Strains in Metal Components. College of Aeronautics Report 97, 1956.Google Scholar
5. Fessler, H. and Haines, D. J. A Photoelastic Technique for Strain Measurement on Flat Aluminium Alloy Surfaces. British Journal of Applied Physics, Vol. 9, p. 282, July 1958.Google Scholar
6. D'Agastino, J., Drucker, D. C., Liu, C. K. and Mylonas, C. An Analysis of Plastic Behaviour of Metals with Bonded Birefringent Plastic. Proceedings of the Society for Experimental Stress Analysis, Vol. XII, No. 2, p. 115, 1955.Google Scholar
7. Zandman, F. Stress Analysis by Photo-Elastic Varnishes. Acier Stahl Steel No. 9, p. 356, 1956.Google Scholar
8. Noral Data Sheet, Northern Aluminium Co. Ltd., Banbury.Google Scholar
9. Instruction Sheet CI. CIBA (A.R.L.) Ltd., Duxford, Cambridge.Google Scholar
10. Instruction Sheet A4. CIBA (A.R.L.) Ltd., Duxford, Cambridge.Google Scholar
11. Frocht, M. M. and Hill, H. N. Stress Concentration Factors around a Central Circular Hole in a Plate Loaded through a Pin in the Hole. American Society of Mechanical Engineers, Vol. 62, p. A5, 1940.Google Scholar