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Southwell and lundquist plots for struts suffering subbuckling cyclic excursions

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Abstract

An experimental investigation into the effects of subbuckling low-frequency cyclic hysteresis upon a range of imperfection-sensitive circular hollow section struts has involved a novel application of the Southwell and Lundquist semi-empirical plot procedures. A static strut testing procedure was modified to provide for the inclusion of cyclic action phases, these cyclic excursions possessing amplitudes that constrained behavior to the subbuckling compression regime throughout. Cyclic action was introduced at some prescribed static axial compression, buckling being statically induced upon completion of the cyclic action phase. For each strut test, appropriate semi-empirical plots were determined, where possible, for both pre- and post-cyclic action phase static data sets, each successful plot thereby consisting of a respective pair of linear loci. It is deemed that such bilinear loci be parallel, indicating no change in boundary conditions or effective length, but offset, indicating cyclic hysteresis amplification of any initial strut imperfection. This bilinear technique is shown to be particularly useful in assessing quality of experimentation and in providing imperfection data applicable to the analysis of nominally static struts suffering subbuckling cyclic action. Design implications are briefly identified for completeness. Serviceability considerations are shown to be the dominant issue.

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Abbreviations

A :

cross-sectional area

a o1,a os :

Lundquist and Southwell estimates ofw oc

E :

direct (Young's) modulus

f :

frequency (1/16 Hz)

I :

second moment of area

n c :

number of cycles employed (1000 cycles)

P :

axial loading

P b :

buckling load (fully static)

P bc :

post-cyclic action phase static buckling load

P c :

Euler or critical load

P c1,P cs :

Lundquist and Southwell estimates ofP c

P mn :

axial load at which cyclic action phase initiated/ECCS load

P′, w′ :

Lundquist pivot coordinates

r :

radius of gyration

u :

axial displacement

u a :

half amplitude

u mn :

mean axial displacement during cyclic action phase

w c :

central transverse displacement of a pin-ended strut under axial loadP

w oc :

initial transverse displacement of a pinended strut under axial loadP=0

w c ′:

cyclic step

ℓ:

effective length

1,ℓ s :

Lundquist and Southwell estimates of ℓ

Δa os , Δa o1 :

difference between respective pre- and post-cyclic Southwell and Lundquist imperfection parameter estimates

λ m :

modified slenderness ratio

σ y :

yield stress

References

  1. Kirby, P.A. and Nethercott, D.A., Design for Structural Stability, Granada Publishing, foreword by M. Horne, vii–viii (1979).

  2. Southwell, R.V., “On the Analysis of Experimental Observations in the Problems of Elastic Stability,”Proc. Roy. Soc., London, Ser. A,135,601–616 (1932).

    Google Scholar 

  3. Spencer, H.H. andWalker, A.C., “Critique of Southwell Plots with Proposals for Alternative Methods,Experimental Mechanics,15 8 (1975).

    Google Scholar 

  4. CIRIA Report SP18, “Long Term Research and Development Requirements in Civil Engineering,” CIRIA Inst. of Civil Eng., 47–57 and 87–112 (1981).

  5. Bjorhovde, R., “Research Needs in Stability of Metal Structures,”J. Struct. Div., ASCE,106,ST12 (Dec. 1980).

    Google Scholar 

  6. Hirst, P. and Taylor, N., “Strut Behaviour Subject to Pre-Buckling Cyclic Loading,” Applied Solid Mechanics,2,Strathclyde Univ. (April 1987).

  7. Hirst, P.B., “Buckling Behavior of Slender Structural Elements Under Interactive Axial Static and Cyclic Loading,” PhD Thesis, Sheffield City Polytechnic (1987).

  8. Leicester, R.H., “Southwell Plot for Beam ColumnsJ. Eng. Mech. Div., ASCE,96,EM6 (Dec. 1970).

    Google Scholar 

  9. Taylor, N. and Hirst, P., “Computerized Large Scale Strut Testing — Interaction Between Experimental and Numerical Models,” Proc. 3rd Int. Conf. on Comp. Meths. and Exp. Meas,1,Porto Carras (Sept. 1986).

  10. Roorda, J., “Some Thoughts on the Southwell Plot,”J. Eng. Mech. Div., ASCE,93,EM6 (Dec. 1967).

    Google Scholar 

  11. Allen, H.G. and Bulson, P.S., Background to Buckling, McGraw-Hill, 81–85 (1980).

  12. Lundquist, E.E., “Generalized Analysis of Experimental Observations in Problems of Elastic Stability,” NACA TN658, Washington (1938).

  13. Snijder, H.H. and Bijlaard, F.S.K., “The Influence of End Restraints on the Maximum Strength of Centrally Loaded Steel Columns in Braced Frames,” J. Constructional Steel Res.,5 (1985).

  14. Jones, S.W., Nethercot, D.A. andKirby, P.A., “Influence of Connection Stiffness on Column Strength,”The Struct. Eng.,65A (11),399–405 (Nov. 1987).

    Google Scholar 

  15. Croll, J.G.A. and Walker, A.C., Elements of Structural Stability, Macmillan Press, 83–84 (1972).

  16. Trahair, N.S., The Behavior and Design of Steel Structures, Chapman and Hall, 54–55 (1977).

  17. Smith, G.N., Elements of Soil Mechanics, Crosby Lockwood, 29–35 (1968).

  18. Stubbins, J.F. and Alexander, W.R., “Effects of Fatigue in the Elastic Regime on the Mechanical Properties of Nuclear Pressure Vessel Steels,” Conf. Proc. on Ferritic Alloys for Use in Nuclear Energy Technologies, Snowbird, UT (June 1983).

  19. Tall, L., “Stub Column Test Procedure,”Doc. X-282-61, Lab. Rep. No. 220A, Lehigh Univ., Bethlehem, PA (1961).

    Google Scholar 

  20. Ellinas, C.P. et al., Buckling of Offshore Structures, Granada, 6–17 (1984).

  21. Wood, W.A., The Study of Metal Structures and Their Mechanical Properties, Pergamon Press (1979).

  22. Stamenkovic, A. andGardner, M.J., “Effect of Residual Stresses on the Column Behaviour of Hot-finished Structural Steel Sections,”Proc. Inst. Civil Eng., Part 2,75,599–616 (1983).

    Google Scholar 

  23. British Standards Institution, “Hot-rolled Structural Steel Sections, Part 2: Hollow Sections,” BSI, London, BS 4848, Part 2 (1975).

  24. Johnstone, B.G., “Third SSRC Guide with Column Design Applications,”J. Struct. Div., ASCE 103 (ST7),1359–1376, (1977).

    Google Scholar 

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Taylor, N., Hirst, P. Southwell and lundquist plots for struts suffering subbuckling cyclic excursions. Experimental Mechanics 29, 392–398 (1989). https://doi.org/10.1007/BF02323856

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  • DOI: https://doi.org/10.1007/BF02323856

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