Investigation of Web-Hole Effect on Web Crippling Strength of Cold Formed Channel Section

Abstract

This paper presents an experimental, theoretical and numerical investigation on lipped channel sections with circular web holes subjected to two loading conditions as specified in the American specifications for cold formed steel structures, namely, interior-two-flange and end-two-flange. For interior-two-flange, the web holes are provided (i) at center beneath bearing plate and (ii) at offset distance. For end-two-flange, web holes are provided at (i) center beneath bearing plate and (ii) 1/4th distance of the specimen. The test strength is compared with design strength obtained from American specification (AISI 2007), Australian and New Zealand specification (AS/NZS 4600), British Standards (BS 5950-Part 5 1998) and Indian Standards (IS 801 1975) codal provisions. In the commercially available Finite Element Software ANSYS 12.0, specimens are modeled and are compared with test results of the web crippling strength subjected to interior-two-flange loading and end-two-flange as that of experimental test setup. The SHELL181 element type for channel section and SOLID 45 element type for bearing plate was assumed for the finite element analysis. The finite element results demonstrate the ultimate load carrying web crippling strength and web crippling displacements are obtained. It was observed that length of bearing, web depth and position of web hole has an effect on web crippling strength.

Keywords: Web crippling strength, web-hole effect, ITF and ETF load cases, FEM ANSYS, AISI specifications