Numerical investigation of steel-timber composite beams with cold-formed omega girders. Part 2: Beams with modifications and reinforced beams

Abstract

This paper is part 2 of a numerical investigation of steel-timber composite beams with cold-formed omega girders and laminated veneer lumber slabs. After conducting a preliminary analysis of the composite beam cross-section in part 1 of the paper, a modification to the cross-section and a reinforcing method were proposed in part 2. In order to increase the load-bearing capacity of the beam, modifications, such as placing a metal sheet inside of the girder or placing a channel outside of the girder, were proposed. These modifications can be made at the production stage of the steel girders. The modification in form of a channel placed outside the omega girder provided the highest increase in the load-bearing capacity. However, the mass of the modified beam with the channel was 29.6% greater than the mass of the reference beam, and the modifying the girder using channels poses a particular challenge. For this reason, the modifications in the form of a flat sheet can be used instead of the channel. The sheet metal may be located inside the omega section to increase the aesthetics of the beam. Furthermore, the effectiveness of the carbon fibre reinforced polymer tape was analysed as a method of beam reinforcement at the building operation stage. The use of the tape resulted in increased load-bearing capacity. However, the increase in the load-bearing capacity of the beam may be limited because of the yielding of the support zone.