Session Dates
15 Oct 1998
Abstract
Cold-formed Channel- and Z-sections subject to both flexure and torsion may undergo distortional buckling where the flange and lip rotate about the flange/web junction. This mode of failure is prevalent in purlin sections when lateral deformation of the section is prevented and when the sections are manufactured from high strength steel. In an attempt to prevent distortional buckling, some manufacturers have added additional return lips to the flange lips to produce complex edge stiffeners. The Australian/New Zealand Standard for Cold-Formed Steel Structures includes design rules for determining the distortional buckling strength of cold-formed beam and column sections. These design rules require the computation of the elastic distortional buckling stress. Appendix D of ASINZS 4600 provides design rules for computing the elastic distortional buckling stress of general channels in compression, simple lipped channels in compression and simple lipped Channel- and Z-sections in bending about an axis perpendicular to the web. The paper describes general formulations for computing the elastic distortional buckling stresses of sections with return lips including those with sloping lips and return lips. The accuracy of the formulations is compared with the results for a large range of section geometries using a finite strip buckling analysis which can be regarded as providing accurate solutions for distortional buckling stress. Explicit expressions are presented in the paper for the flange properties.
Department(s)
Civil, Architectural and Environmental Engineering
Research Center/Lab(s)
Wei-Wen Yu Center for Cold-Formed Steel Structures
Meeting Name
14th International Specialty Conference on Cold-Formed Steel Structures
Publisher
University of Missouri--Rolla
Document Version
Final Version
Rights
© 1998 University of Missouri--Rolla, All rights reserved.
Document Type
Article - Conference proceedings
File Type
text
Language
English
Recommended Citation
Merrick, John T.; Hancock, Gregory J.; and Bamach, M. R., "Distortional Buckling Formulae for Thin Walled Channel and Z-sections with Return Lips" (1998). CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018). 3.
https://scholarsmine.mst.edu/isccss/14iccfsss/14iccfsss-session1/3
Distortional Buckling Formulae for Thin Walled Channel and Z-sections with Return Lips
Cold-formed Channel- and Z-sections subject to both flexure and torsion may undergo distortional buckling where the flange and lip rotate about the flange/web junction. This mode of failure is prevalent in purlin sections when lateral deformation of the section is prevented and when the sections are manufactured from high strength steel. In an attempt to prevent distortional buckling, some manufacturers have added additional return lips to the flange lips to produce complex edge stiffeners. The Australian/New Zealand Standard for Cold-Formed Steel Structures includes design rules for determining the distortional buckling strength of cold-formed beam and column sections. These design rules require the computation of the elastic distortional buckling stress. Appendix D of ASINZS 4600 provides design rules for computing the elastic distortional buckling stress of general channels in compression, simple lipped channels in compression and simple lipped Channel- and Z-sections in bending about an axis perpendicular to the web. The paper describes general formulations for computing the elastic distortional buckling stresses of sections with return lips including those with sloping lips and return lips. The accuracy of the formulations is compared with the results for a large range of section geometries using a finite strip buckling analysis which can be regarded as providing accurate solutions for distortional buckling stress. Explicit expressions are presented in the paper for the flange properties.
