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Analytical effective width equations for limit state design of thin plates under non-homogeneous in-plane loading

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Abstract

The effective width concept has been widely used in engineering practice for the computation of ultimate strength of slender members. Many design codes employ this concept in order to compensate for the stiffness reduction in the post-buckling state. Extensive work was done to develop effective width equations for plates under uniform compression, while little attention has been given for plates under non-homogeneous in-plane loading. North American, British and European design codes provide only expressions for the computation of the elastic buckling loads for plates under this load combination, while the effective width calculation is based on the uniformly compressed plates. It will be shown that due to the non-uniformity of the applied load, the stress characteristics in the post-buckling state are different from the uniform compression case, thus requiring special treatments. The paper presents analytical closed form expressions for the computation of effective width of thin plates under non-homogeneous in-plane loading. The longitudinal edges are assumed to be straight and free to translate in the plane of the plate. The proposed expressions are very useful for limit state design of slender I-sections of beam columns or channel sections under this general type of loading. They enable the designers to compute the effective width of the section with the aid of simple formulas that, for design purposes, are suitable for hand-calculation and avoid the cost and effort that any numerical non-linear analysis may require.

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Abbreviations

a :

Length of the plate

b :

Width of the plate

b e , be1, be2:

Effective widths

D :

Plate bending rigidity per unit width, Et 3/12(1−v 2)

E :

Elastic modulus

f, fo:

Amplitudes of the out-of plane deflection and initial imperfection, respectively

m :

Number of half waves in the longitudinal direction

N 1 :

Compressive force at the heavily loaded edge

N x , N y :

Compressive forces per unit length in the x and y directions, respectively

t :

Thickness of the plate

u, v:

In-plane displacements in the x, y direction, respectively

w, wo:

Out of plane deflection and initial imperfection, respectively

β :

Plate aspect ratio

η :

Non-dimensional width, y/b

v :

Poisson ratio

ξ :

Non-dimensional length, x/a

Φ:

Stress function

\({\varphi}\) :

Limit state resistance factor of safety

σ 1 :

Stress intensity at the heavily loaded edge

σ x , σ y :

Membrane stresses acting in the x, y direction, respectively

σ xy :

Membrane shear stress acting in the x, y plane

σ o :

Yield stress of the plate

σ cr :

Critical stress of the plate

σmax1, σmax2:

Maximum compressive edge stresses

σ i :

Induced stresses due to applied loads

ε x , ε y :

Middle surface membrane strains in the x, y directions, respectively

γ xy :

Middle surface shear strain

κ :

A parameter equals m/β

Ψ:

Stress gradient coefficient

References

  1. Schuette, E.H., McCulloch, J.C.: Charts for the minimum weight design of multiweb wings in bending. NACA TN 1323 (1947)

  2. Johnson J.H., Noel G.R.: Critical bending stress for flat rectangular plates supported along all edges and elastically restrained against rotation along the unloaded compression edge. J. Aero. Sci. 19, 535–540 (1953)

    Google Scholar 

  3. Walker A.C.: Maximum loads for eccentrically loaded thin-walled channel struts. IABSE 28, 169–181 (1968)

    Google Scholar 

  4. Walker A.C.: Flat rectangular plates subjected to a linearly-varying edge compressive loading. In: Chilver, A.H.(eds) Thin Walled Structures, pp. 208–247. Chatto and Windus, England (1967)

    Google Scholar 

  5. Walker A.C.: Local instability in plates and channel struts. ASCE 92, 39–55 (1966)

    Google Scholar 

  6. Rhodes J., Harvey J.M., Fok W.C.: The load carrying capacity of initially imperfect eccentrically loaded plates. Int. J. Mech. Sci. 17, 161–175 (1975)

    Article  Google Scholar 

  7. Rhodes J., Harvey J.M.: Plain channel section struts in compression and bending beyond the local buckling load. Int. J. Mech. Sci. 8, 511–519 (1976)

    Article  Google Scholar 

  8. Rhodes J., Harvey J.M.: Examination of plate post-buckling behaviour. J. Eng. Mech. ASCE 103, 461–478 (1977)

    Google Scholar 

  9. Loughlan L.: The ultimate load sensitivity of lipped channel columns to column axis imperfection. Thin Walled Struct. 1, 75–96 (1983)

    Article  Google Scholar 

  10. Usami T.: Post-buckling of plates in compression and bending. ASCE ST3 108, 591–609 (1982)

    Google Scholar 

  11. Lau S.C.W., Hancock G.J.: Buckling of thin flat-walled structures by a spline finite strip method. Thin Walled Struct. 4, 269–294 (1986)

    Article  Google Scholar 

  12. Bradford M.A.: Buckling of longitudinally stiffened plates in bending and compression. Can. J. Civ. Eng. 16, 607–614 (1989)

    Google Scholar 

  13. Jana P., Bhaskar K.: Stability analysis of simply-supported rectangular plates under non-uniform uniaxial compression using rigorous and approximate plane stress solutions. Thin Walled Struct. 44(5), 507–516 (2006)

    Article  Google Scholar 

  14. Wang X., Wang X., Shi X.: Differential quadrature buckling analyses of rectangular plates subjected to non-uniform distributed in-plane loadings. Thin Walled Struct. 44(8), 837–843 (2006)

    Article  Google Scholar 

  15. Bambach M.R.: Local buckling and post-local buckling redistribution of stress in slender plates and sections. Thin Walled Struct. 44(10), 1118–1128 (2006)

    Article  Google Scholar 

  16. Yu C., Schafer B.: Effect of longitudinal stress gradient on the ultimate strength of thin plates. Thin Walled Struct. 44(7), 787–799 (2006)

    Article  Google Scholar 

  17. Szychowski A.: The stability of eccentrically compressed thin plates with a longitudinal free edge and with stress variation in the longitudinal direction. Thin Walled Struct. 46(5), 494–505 (2008)

    Article  Google Scholar 

  18. Wang X., Rammerstorfer F.G.: Determination of effective breadth and effective width of stiffened plates by finite strip analyses. Thin Walled Struct. 26(5), 261–286 (1996)

    Article  Google Scholar 

  19. Von-Karman T., Sechler E.E., Donnell L.H.: The strength of thin plates in compression. Trans. ASME 54, 53–57 (1932)

    Google Scholar 

  20. Winter, G.: Thin-walled structures, theoretical solutions and test results, preliminary publication of the eighth congress. IABSE 101–112 (1968)

  21. Abdel-Sayed G.: Effective width of thin plates in compression. ASCE 95, 2183–2203 (1969)

    Google Scholar 

  22. Dawson R.G., Walker A.C.: Post buckling of geometrically imperfect panels. ASCE 98, 75–94 (1972)

    Google Scholar 

  23. Narayanan R., Chow F.Y.: Effective widths of plates loaded uniaxially. Thin Walled Struct. 1, 165–187 (1983)

    Article  Google Scholar 

  24. Vilnay O., Rockey K.C.: A generalized effective width method for plates loaded in compression. J. Constr. Steel Res. 1, 3–12 (1981)

    Article  Google Scholar 

  25. Beedle, L.S. (ed.): Stability of Metal Structures, a World View, 2nd ed. Structural Stability Research Council USA (1991)

  26. Galambos T.V.: Guide to stability design criteria for metal structures, 5th ed. Structural Stability Research Council, Wiley, New York (1998)

    Google Scholar 

  27. Gaylord, E.H., Gaylord, C. (eds): Structural Engineering Handbook. McGraw-Hill. McGraw-Hill, USA (1990)

    Google Scholar 

  28. Mohammadi B., Najafi A., Ghannadpour S.: Effective widths of compression-loaded of perforated cross-ply laminated composites. Campsite Struct. 75, 7–13 (2006)

    Article  Google Scholar 

  29. Salem A., El Aghoury M., El Dib F., Hanna M.: Ultimate capacity of I-slender section columns. J. Constr. Steel Res. 60(8), 1193–1211 (2004)

    Article  Google Scholar 

  30. Lind N.C., Ravindra M.K., Schorn G.: Empirical effective width formula. ASCE 102, 1741–1757 (1976)

    Google Scholar 

  31. Roorda J., Venkataramaiah K.: Effective width of stiffened cold formed steel plates. Can. J. Civ. Eng. 6, 381–389 (1979)

    Article  Google Scholar 

  32. Faulkner D.: A review of effective plating for use in the analysis of stiffened plating in bending and compression. J. Ship Res. 19, 1–17 (1975)

    Google Scholar 

  33. CSA-2001: Limit State Design of Steel Structures. Canadian Standard Association CAN/CSA-S16–01, Mississauga, Ontario, Canada

  34. CISC-2006: Handbook of Steel Construction. Canadian Institute of Steel Construction, Toronto, Ontario, Canada

  35. AISC: Steel Construction Manual, American Institute of Steel Construction, 13th ed. Chicago, USA (2005)

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Bedair, O. Analytical effective width equations for limit state design of thin plates under non-homogeneous in-plane loading. Arch Appl Mech 79, 1173–1189 (2009). https://doi.org/10.1007/s00419-009-0296-z

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