engleski

Numerical study of the behavior of the bolted shear connection in cold-formed steel-concrete composite beam

Nowadays, composite steel-concrete systems are among the most cost-effective construction systems for application in multi-storey buildings as they combine structural efficiency and allow accelerated construction speed. Additional optimisation of these systems is possible through the application of cold- formed steel elements and innovative solutions for shear connections. Such optimisation of composite systems is the topic of the LWT-FLOOR project ongoing at the Faculty of Civil Engineering in Zagreb. This paper presents a numerical study of two various cold- formed steel beam types connected to a concrete slab placed within profiled steel sheeting and interconnected using the bolted shear connection. The first cold- formed steel beam type consists of built-up sections using back-to-back cold-formed steel C profiles, while the second type additionally uses a corrugated web inserted between the webs of the cold-formed steel C profiles. To evaluate shear connection behaviour, simulations of the push-out test are performed where either solution with two bolts per rib placed symmetrically or the solution with one bolt per rib placed in a staggered manner is used. Compared to the shear connection with two bolts per rib it is expected that staggered bolt placement would have much less influence on the shear connection strength in the case of cold- formed steel profiles without corrugated web than in the case when the corrugated web is used. Furthermore, a previous study on the behaviour of bolted shear connection in composite systems using cold-formed steel profiles indicates that the proposed values of the reduction factor, 𝑘𝑡 when profiled steel sheeting ribs are placed transverse to the steel beam may be too conservative or, in some cases, even completely unnecessary. Therefore, a numerical study on the composite system using cold-formed steel profiles and the corrugated web was further expanded to evaluate the influence of different parameters on the value of the reduction factor.

composite beam ; cold-formed steel (CFS) ; spot-weld ; built-up section ; composite dowel rib connector ; demountable shear connector

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