A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Effect of openings on the strength of cold formed steel sections
A major inhibition to the wider use of cold formed steel sections in buildings is the difficulty of passing services through the web of the sections. In order to increase the use of cold formed sections, openings may be made in the webs. Openings in the sections may be made during the roll-forming operation, or punched in a separate operation. The intrinsic formability of the thin steel sheet used for cold formed sections also allows for the forming of stiffeners around the openings during manufacture. The stiffeners are beneficial in reducing the tendency for local buckling and improving the moment transfer across the openings. However, there is relatively little guidance on the influence of openings of significant sizes on the design of cold formed sections. In order to help engineers to take advantage of the improved buildability of cold formed sections, the structural implications of the presence of openings were examined thoroughly in this research project. Experimental and theoretical studies, including finite element analysis, were carried out to compare the structural performances of sections with and without openings. The effects of openings on local web buckling, web crippling and moment resistances, and stress distribution around the openings with or without stiffeners were also studied. The research work involved initial tests to assess the range of strength reduction in sections with openings of practical sizes and shapes. Two types of tests were developed, namely, the web crippling (or crushing) tests and the flexural (beam) tests, to investigate the structural performance & the sections in the presence of openings. An extensive test programme of four test series with a total of 29 beam tests and 47 web crippling tests was carried out on sections with single openings. The specimens were tested to failure. In order to extend the investigation to sections with multiple openings, a further test programme of two test series with a total of 12 beam tests and 10 web crippling tests was also conducted. It was found that the presence of openings in cold formed sections may not reduce their web crippling and moment resistances significantly.
Effect of openings on the strength of cold formed steel sections
A major inhibition to the wider use of cold formed steel sections in buildings is the difficulty of passing services through the web of the sections. In order to increase the use of cold formed sections, openings may be made in the webs. Openings in the sections may be made during the roll-forming operation, or punched in a separate operation. The intrinsic formability of the thin steel sheet used for cold formed sections also allows for the forming of stiffeners around the openings during manufacture. The stiffeners are beneficial in reducing the tendency for local buckling and improving the moment transfer across the openings. However, there is relatively little guidance on the influence of openings of significant sizes on the design of cold formed sections. In order to help engineers to take advantage of the improved buildability of cold formed sections, the structural implications of the presence of openings were examined thoroughly in this research project. Experimental and theoretical studies, including finite element analysis, were carried out to compare the structural performances of sections with and without openings. The effects of openings on local web buckling, web crippling and moment resistances, and stress distribution around the openings with or without stiffeners were also studied. The research work involved initial tests to assess the range of strength reduction in sections with openings of practical sizes and shapes. Two types of tests were developed, namely, the web crippling (or crushing) tests and the flexural (beam) tests, to investigate the structural performance & the sections in the presence of openings. An extensive test programme of four test series with a total of 29 beam tests and 47 web crippling tests was carried out on sections with single openings. The specimens were tested to failure. In order to extend the investigation to sections with multiple openings, a further test programme of two test series with a total of 12 beam tests and 10 web crippling tests was also conducted. It was found that the presence of openings in cold formed sections may not reduce their web crippling and moment resistances significantly.
Effect of openings on the strength of cold formed steel sections
Einfluß der Öffnungen auf die Festigkeit kaltgeformter Stahlbauelemente
Godwin, M.J. (author) / Chung, K.F. (author) / Griffiths, D.A. (author)
1998
189 Seiten, 116 Bilder, 42 Tabellen, 27 Quellen
Report
English
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