Local buckling and shift of effective centroid of cold-formed steel columns

  • Young, Ben (Department of Civil Engineering, The University of Hong Kong)
  • Received : 2004.07.09
  • Accepted : 2004.11.15
  • Published : 2005.04.25


Local buckling is a major consideration in the design of thin-walled cold-formed steel sections. The main effect of local buckling in plate elements under longitudinal compressive stresses is to cause a redistribution of the stresses in which the greatest portion of the load is carried near the supporting edges of the plate junctions. The redistribution produces increased stresses near the plate junctions and high bending stresses as a result of plate flexure, leading to ultimate loads below the squash load of the section. In singly symmetric cross-sections, the redistribution of longitudinal stress caused by local buckling also produces a shift of the line of action of internal force (shift of effective centroid). The fundamentally different effects of local buckling on the behaviour of pin-ended and fixed-ended singly symmetric columns lead to inconsistencies in traditional design approaches. The paper describes local buckling and shift of effective centroid of thin-walled cold-formed steel channel columns. Tests of channel columns have been described. The experimental local buckling loads were compared with the theoretical local buckling loads obtained using an elastic finite strip buckling analysis. The shift of the effective centroid was also compared with the shift predicted using the Australian/New Zealand and American specifications for cold-formed steel structures.


  1. AISI. (1946), Specification for the Design of Light Gauge Steel Structural Members, American Iron and Steel Institute, New York.
  2. AISI. (1996), Specification for the Design of Cold-Formed Steel Structural Members, American Iron and Steel Institute, Washington, DC.
  3. Aust/NZ. (1996), Cold-formed Steel Structures, Australian/New Zealand Standard, AS/NZS 4600:1996, StandardsAustralia, Sydney, Australia.
  4. Galambos, T.V. (1998), Guide to Stability Design Criteria for Metal Structures, 5th Edition, John Wiley & Sons Inc., New York.
  5. Hancock, G.J. (1978),"Local, distortional and lateral buckling of I-beams", J. Struct. Div., ASCE, 104(11), 1787-1798.
  6. Papangelis, J.P. and Hancock, G.J. (1995),"Computer analysis of thin-walled structural members", Comput. Struct., 56(1), 157-176.
  7. Rasmussen, K.J.R. and Hancock, G.J. (1993),"The flexural behaviour of fixed-ended channel section columns",Thin-Walled Structures, 17(1), 45-63.
  8. Rhodes, J. and Harvey, J.M. (1977),"Interaction behaviour of plain channel columns under concentric or eccentricloading", Proc. of the Second Int. Colloquium on the Stability of Steel Structures, Liege, 439-444.
  9. Venkataramaiah, K.R. and Roorda, J. (1982),"Analysis of local plate buckling experimental data", Proc. of the Sixth Int. Specialty Conf. on Cold-Formed Steel Structures, St. Louis, Missouri, 45-74.
  10. von Karman, T., Sechler, E.E. and Donnell, L.H. (1932),"The strength of thin plates in compression", Transactions, Applied Mechanics Division, ASME, 54, APM-54-5, 53-57.
  11. Winter, G. (1947),"Strength of thin steel compression flanges", Transactions, ASCE, 112, 527-554.
  12. Winter, G. (1968),"Thin-walled structures - Theoretical solutions and test results", Preliminary Publications of the Eighth Congress, International Association for Bridge and Structural Engineering (IABSE), 101-112.
  13. Young, B. (1997),"The behaviour and design of cold-formed channel columns", PhD Thesis, Vol. 1 & 2, Department of Civil Engineering, University of Sydney, Australia.
  14. Young, B. and Rasmussen, K.J.R. (1998a),"Tests of fixed-ended plain channel columns", J. Struct. Eng., ASCE, 124(2), 131-139.
  15. Young, B. and Rasmussen, K.J.R. (1998b),"Design of lipped channel columns", J. Struct. Eng., ASCE, 124(2), 140-148.
  16. Young, B. and Rasmussen, K.J.R. (1999a),"Behaviour of cold-formed singly symmetric columns", Thin-Walled Structures, 33(2), 83-102.
  17. Young, B. and Rasmussen, K.J.R. (1999b),"Shift of effective centroid of channel columns", J. Struct. Eng.,ASCE, 125(5), 524-531.
  18. Young, B. and Rasmussen, K.J.R. (2003),"Measurement techniques in the testing of thin-walled structural members", Experimental Mechanics, 43(1), 32-38.

Cited by

  1. Column design of cold-formed stainless steel slender circular hollow sections vol.6, pp.4, 2006,
  2. Behaviour of cold formed lipped angles in transmission line towers vol.44, pp.9, 2006,
  3. Buckling analysis of high strength stainless steel stiffened and unstiffened slender hollow section columns vol.63, pp.2, 2007,