Numerical investigation of built-up cold-formed steel beams connected by spot welding

Abstract

<p>Built-up cold-formed steel elements are efficient structural elements, very attractive due to material savings, but also for ease of construction. The connection between the built-up beam components can be easily obtained by screws, but the developments in the welding process also led to other solutions like spot welding. The WELLFORMED research project, conducted within the CEMSIG Research Center of the Politehnica University of Timisoara, proposes to study a new technological solution for built-up beams made of corrugated steel sheets for the web and thin-walled cold-formed steel profiles for the flanges, connected by spot welding. Within the research project, the experimental work included tensile-shear tests on the lap joint welded specimens, where different combinations of steel sheets with various thicknesses were tested and, tests on two full-scale beams in bending. The paper briefly summarizes the results of the experimental program and extends the research by numerical analyses to demonstrate the potential of this solution for standardization and industrial manufacturing. Based on the validation of the numerical model, the paper presents the influence of several parameters i.e.: (1) the initial imperfections, (2) the number and distance between spot welding on flanges, (3) the thickness of the flanges, (4) the thickness of the corrugated web and (5) the thickness of the shear panel. From the parametric study, it results that the bearing capacity of the corrugated web beams made of cold-formed steel components is highly affected by the stability of the components and less affected by the configuration and the number of spot welding.</p>

Parametric Finite Element Analyses of Lightweight Cold‐formed Steel‐concrete Composite Floor Beams

“…Therefore, besides the structural advantages of such a system, the potential for automated series fabrication of the new technological solutions is another great advantage. The numerical parametric research on the calibration and validation of the numerical models with additional experimental tests considering the influence of web openings has resulted in several papers [26][27][28][29]. These studies confirmed the excellent behaviour of SW built-up corrugated web beams.…”

Numerical study on bending resistance of cold‐formed steel back‐to‐back built‐up elements

“…Previous studies, considering appropriate imperfections, material parameters, mesh size and element type, have shown that finite element (FE) models can be used to accurately predict the load-bearing capacity and post-buckling behaviour of the built-up cold-formed steel beams [1,15].…”

“…According to [15,18], global imperfections are taken with the initial global bow imperfections with a magnitude of approximately L/1000 (L is the span of the beam). Support conditions were defined on the nodes at the ends of the beam (control points) coupled with beam end cross-sections as simply supported end conditions.…”

“…In order to obtain realistic results from the finite element nonlinear analysis, plastic strains were included in the material definition, according to EN1993-1-5 [19]. The measured stress-strain curves, based on tensile tests of coupons cut from the thin-walled cross-section of the same thickness as used in FE analyses, were included in the model.…”

Numerical investigations on built‐up cold‐formed steel beams for long spans

“…The use of built-up cold-formed steel elements is common for moderate spans due to the stability problems, but numerical studies [5], [6] can be used to accurately predict the load carrying capacity and post-buckling behaviour considering appropriate imperfections, material parameters, mesh size and element type, and can be extended to long span behaviour assessment.…”