Civil Engineering Study 97-6
PREFACE The spacing of connectors in compression elements of built-up flexural members was evaluated both experimentally and analytically at the University ofMissouri-Rolla (UMR) under the sponsorship of the American Iron and Steel Institute. A computational model was developed for determining the bending capacity of single-fluted sections with cover plates that do not have edge stiffeners. The results of the investigation are presented and recommendations are made for design of single-flute cross sections having cover plates without edge stiffeners. Previous research developments by Yener, at Purdue University, and Luttrell, at the University of West Virginia, were compared to the UMR experimental data, which consisted of 83 single flute built-up hat sections with and without edge stiffened cover plates. All hat sections were tested as simple span beams with cover plates in compression. The buckling behavior of edge stiffened cover plates and cover plates without edge stiffeners was investigated and discussed herein. The effective length factor and plate buckling coefficient were determined from the test results. A discussion of the correlation between the UMR experimental findings and the work of both Luttrell and Yener is presented. The UMR research validates the AISI Design Specification spacing criteria (Section D1.2) which restricts spacing to a value that will prevent any separation of the cover plate from the hat section between the connectors. This provision, however, is very conservative when applied to a section in bending because it yields very small connector spacings. The spacing of the connectors may be increased beyond that required by Section D1.2 which results in a reduction of strength. Tests have indicated that the capacity of the hat section is not diminished due to the onset of plate buckling in the cover plate. The hat section will continue to carry additional load because of the post-buckling strength provided by the cover plate. This report is based on a thesis submitted to the Faculty of the Graduate School of the University ofMissouri-Rolla in partial fulfillment of the requirements for the degree of Masters of Science in Civil Engineering. Technical guidance for this investigation was provided by the American Iron and Steel Institute's Subcommittee on Flexural Members (J.N. Nunnery, Chairman) and Connections (M.Golovin, Chairman). The Subcommittees' guidance is gratefully acknowledged. Thanks are also extended to H. H. Chen, D. F. Boring and S.P. Bridgewater, AISI staff, for their assistance.
Civil, Architectural and Environmental Engineering
Wei-Wen Yu Center for Cold-Formed Steel Structures
American Iron and Steel Institute
Cold-Formed Steel Series
Missouri University of Science and Technology
© 1997 Missouri University of Science and Technology, All rights reserved.
Report - Technical
Jones, Michael L.; LaBoube, Roger A.; and Yu, Wei-wen, "Spacing of connections in compression elements for cold-formed steel members (beams)" (1997). Center for Cold-Formed Steel Structures Library. 50.