Finite element modelling of composite cold-formed steel flooring systems

Abstract

The findings from a numerical investigation into the degree of composite action that may be mobilised within floor systems comprising cold-formed steel joists and wood-based particle boards are presented herein. Finite element models have been developed, simulating all the components of the examined systems, as well as the interaction between them. The models include initial geometric imperfections, the load-slip response of the fasteners employed to achieve the shear connection as well as both geometric and material nonlinearities. The developed models were first validated against 12 physical tests reported in the literature, which showed them to be capable of accurately capturing the load-deformation curves and failure modes exhibited by the tested specimens. Parametric studies were then performed to examine the influence of key parameters on the structural behaviour of these systems, including the depth and thickness of the cold-formed steel section, as well as the spacing of the employed fasteners; in total, about 100 systems have been examined. Significant benefits in terms of structural response have been identified from the presented numerical study as a result of the mobilisation of composite action; for the systems investigated, which were of typical, practical proportions, up to 140% increases in moment capacity and 40% increases in stiffness were found. The presented research reveals the substantial gains in structural performance and the influence of the key governing parameters for this novel form of composite construction.

Prestressed cold-formed steel beams: Concept and mechanical behaviour

“…The commercial finite element (FE) analysis package ABAQUS [42], which has been widely used in previous research for the modelling of cold-formed steel members [43,44,45,46,47], is employed to simulate the mechanical behaviour of the prestressed cold-formed steel beams herein. A geometrically and materially nonlinear analysis with imperfections is performed, aiming to understand the mechanical behaviour of the proposed beams and to provide an insight to the scale of the potential benefits that can be derived from prestressing.…”

“…However, in the present paper, the material behaviour is idealised using an elastic, perfectly-plastic material model with no strain hardening to enable direct comparisons to be made with the idealised analytical predictions derived in Section 2. A yield stress of F y,s =491 N/mm 2 and Young's modulus of E s =201 kN/mm 2 are chosen for the cold-formed steel, based on the research conducted by Kyvelou et al [47]. The high-strength steel cable is modelled using an elastic material model with F y,c =1860 N/mm 2 and E c =195 kN/mm 2 , based on [15] and [48] respectively.…”

“…The 4-noded linear S4R [42] shell element with reduced integration and hourglass control is used herein for the modelling of the coldformed steel sections. It has been demonstrated in previous research studies that these elements can replicate the local and distortional buckling that typically occur in cold-formed steel members subjected to bending [45,51,47]. A mesh sensitivity analysis was conducted to determine an appropriate cross-sectional discretization that would be both computationally inexpensive and sufficiently fine to capture the local instabilities with good accuracy.…”

Alternative Fastening Mechanism for Shear Connectors with Cold-Formed Steel Shapes Involved in Composite Sections

“…However, those products require a special tool to make this installation an efficient procedure. Lakkavalli and Liu (2006), Merryfield et al (2016) and Kyvelou et al (2017Kyvelou et al ( , 2018 used self-drilling screws as shear connectors in full-scale bending tests for CFS composite beams. Study factors involved in the researches were connectors spacing and comparison to other types of transfer elements such as bent-up tabs, bolt connectors and puddle welding.…”

Experimental Investigation for Non and Partially Composite Cold-Formed Steel Floor Beams

“…P. Kyvelou et al proposed an experimental investigations in 2017 showed the degree of composite action that can arise between cold-formed steel joists and wood-based flooring panel [10] and [11]. In 2018 P. Kyvelou et al presented a numerical investigation into the degree of composite action that may be mobilized within floor systems comprising cold-formed steel joists and wood-based particle boards [12]. D. C. Fratamicoa et al (2018) studied experiments addressing the buckling and collapse behavior of common built-up coldformed steel (CFS) columns [13].…”