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This paper aims to perform the experimental test and numerical FE analysis of the cold-formed steel frame structure to provide new proposals to improve the strength, rotation capacity, and seismic energy dissipation in these structures. A 3D full-scale three-story CFS frame structure is experimentally investigated under four sets of input data for 100% and 50% scales of Northridge and Kocaeli earthquake acceleration records using the shaking table test. In each test, the frame acceleration and displacement are observed. A FE model is employed to assert the validity of the experimental test. The results indicated that the maximum story drift ratio of the frame ranges from 1.14% to 3.70%. It is observed that the average similarity ratio of the maximum displacement results between FE analysis and shaking table test is 92%. It is shown that the translational stiffness for the system decrease as the earthquake acceleration records decrease. It is also shown that using the image processing technique in the shaking table test can offer much more acceptable and economical solutions in determining the displacement parameters. [ABSTRACT FROM AUTHOR]

We explore, in this paper, the demands and behavior on fasteners supplying sheathing-based bracing of gravity loaded cold-formed studs and wall assemblies. The studies are carried out by shell finite element (FE) models, which are compared to analytical solutions and previously completed laboratory tests conducted by the authors. The connection between the sheathing and the stud should be able to develop enough resistance to restrain global buckling of the studs; therefore, special attention has to be given to the demands on these connections for design. Local buckling and stress concentrations may damage some connections and redistribution of forces should be ensured. Classical practice for determining fastener demand - i.e., the 2% rule - may be deficient. An analytical method developed for determining fastener demand is compared to the FE models presented in this paper; the analytical method results in a reasonable prediction of the fastener forces in wall studs. [ABSTRACT FROM AUTHOR]

This paper presents an investigation on interaction equation between the required flexural strength, M, and the required shear strength, V, of cold-formed C-channels with web holes and bearing stiffeners. The primarily shear condition test was employed to study total 8 back to back lipped C channel sections of 95 and 100 mm depth when bearing stiffeners and circular holes were placed at center and both ends of specimens. The interaction equation were evaluated via Direct Strength Method, DSM, in accordance with the American Iron and Steel Institute for the design of cold-formed steel structural members, AISI 2007. A nonlinear finite element model was developed and verified against the test results in terms of failure buckling modes. It was concluded that the M-V interaction equation for specimens with web stiffeners was conservative where these specimens experienced plastic failure mode rather than local (Msl) or distortional (Msd) buckling mode. Moreover, the results indicated that proposed M-V interaction equation calculated by local buckling strength (Msl) adequately predicted the behavior of specimens with circular web holes. [ABSTRACT FROM AUTHOR]

In conventional composite construction involving hot-rolled steel section, the composite action is usually achieved by using conventional headed shear studs connectors. However, use of headed studs is not practical for cold-formed steel (CFS) section due to its very thin form that is difficult to weld. A suitable bolt and nut type shear connector was proposed; experimental tests were carried out to evaluate its performance. This study also investigated the use of Self-Compacting Concrete (SCC) integrated with CFS by means of bolted shear connectors to develop composite action. Therefore, the objective of this paper was to investigate the performance of bolted shear connectors in SCC integrated with CFS section as composite beam system. Eighteen push-out test specimens comprising of M12, M14 and M16 sized bolted shear connector of grade 8.8 with longitudinal spacings of 150 mm, 250 mm and 300 mm centers were fabricated, cast and tested until failure. The experimental results showed that all bolted shear connectors possessed a good shear resistance capacity. Not much difference in strength capacity of specimens with M14 and M16 bolted shear connectors was found, perhaps due to CFS failure. Varying the size and longitudinal spacing of the bolted shear connectors revealed that the connectors' strength capacity changed slightly between M14 and M16 bolts specimens but, significantly for M12 bolt specimens. [ABSTRACT FROM AUTHOR]

This paper presents both the analytical and theoretical investigations on ultimate load carrying capacity and behaviour of CFS unlipped channels with their ends fixed and subjected to axial compression. The numerical studies have been carried out in the elastic as well as in the plastic ranges of loading. The slenderness ratio of the channels chosen is 40, 80,100 and 120. Three different web depths [shallow, medium and deep] with five thicknesses have been chosen. In addition to the numerical studies, comparison with the design strengths predicted by using North American Standards for CFS structures. It is observed that the design strength predicted by the specifications are conservative for axially loaded columns. In the present investigation, an attempt is made to study the ultimate load carrying capacity and the mode of failure. Load versus axial shortening behaviour has been studied for various slenderness ratios for a few specimens. [ABSTRACT FROM AUTHOR]