Flexural Strength Behaviour of Bolted Built-Up Cold-Formed Steel Beam with Outstand and Extended Stiffener

Cold-formed steel (CFS) is a popular structural and non-structural material that is utilised as roof truss, wall panel and storage racks. But nowadays, CFS is selected and proposed as column and beam in building construction. CFS with open-section and very thin thickness is prone to deform and buckle in large condition. Therefore, the problem must be solved by proposing a new section that is matched up or formed of two or more open-sections to be one new section, shape and cross-section area. There are two types of channel-section and a connection is used to produce a bolted built-up CFS beam in the study. The first type is jointed with bolt and nut on stiffener or lipped, which is known as outstand stiffener, and another type is connected by locating the bolt and nut on web element and recognised as extended stiffeners. The objective of the study is to determine the flexural strength and load-deformation behaviour of both types of bolted built-up CFS section. Then, the experimental result is verified with the Standard of Practice, American Iron and Steel Institute and BS EN 1993-1-3, Design of steel structures (2006). As a result, bolted built-up CFS beam with extended stiffener and a span of bolt with constant value of 22.5mm is expressed as a good result of flexural strength. In addition, the flexural strength of both beams is dependent only on spacing or bolt location.