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This paper presents an experimental study of cold formed steel frames sheathed by fibre-cement boards (FCB) under cyclic lateral loading. Four full scale fibre-cement shear walls were tested. Of particular interests are the specimens maximum lateral load capacity and the load–deformation behaviour as well as a rational estimation of the seismic response modification factor, R factor. The study also looks at the failure modes of the systems and investigates the main factors contributing to the ductile response of the CFS shear walls in order to suggest improvements so that the FCB sheathed walls respond plastically with a significant drift and without any risk of brittle failure such as connection failure or fibre-cement board fracture. Both double-sided and single-sided FCB shear panels as well as a new proposed configuration were studied. The study shows that while the overall performance of the currently in-use FCB sheathed lateral resistant system under cyclic loads is not satisfactory with a small average R factor of 2.5, the proposed FCB lateral resistant system can be considered as a reliable system with a much higher value of R factor of 5. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a non-linear finite element analyses in order to optimize the seismic characteristics of strap-braced cold formed steel shear walls enhanced with brackets in the four interior corners of the wall. The numerical models presented here are verified based on experimental tests considering different structural characteristics including: material nonlinearity, geometrical imperfection, residual stresses and perforations. A comparison between the numerical simulations and the test results shows a good agreement proves that the finite element analysis can be used effectively to predict the ultimate capacity of strap-braced CFS shear panels. A total of 16 models with different variants of bracket length are investigated. Of particular interests were the specimens'' maximum lateral load capacity and deformation behavior in addition to a rational estimation of the seismic response modification factor. Preliminary conclusions presented in this paper, refer to the optimum seismic characteristics of strap-braced CFS shear walls and the corresponding dimensions and configuration. [Copyright &y& Elsevier]

Abstract: Detailed investigation of the lateral performance of K-braced cold-formed steel structures and their response modification coefficients, R factor, are presented in this paper. A total of 12 full-scale 2.4×2.4m specimens of different configurations are considered, and the responses investigated under a standard cyclic loading regime. Of particular interest are the specimens'' maximum lateral load capacity and deformation behavior as well as a rational estimation of the seismic response modification factor. The study also looks at the failure modes of the system and investigates the main factors contributing to the ductile response of the CFS walls in order to suggest improvements so that the shear steel walls respond plastically with a significant drift and without any risk of brittle failure, such as connection failure or stud buckling. A discussion on the calculated response factors in comparison to those suggested in the relevant codes of practice is also presented. [Copyright &y& Elsevier]

Abstract: Experimental investigations were conducted to evaluate the lateral seismic characteristics of light-weight knee-braced cold-formed steel structures. In all, four full-scale 2.4×2.4m2 specimens with different configurations were tested under a standard cyclic loading regime. This paper focuses on the specimens'' maximum lateral load capacity and deformation behavior and provides a rational estimate of the seismic response modification factor, R, of knee-braced walls. The study also looks at the failure modes of the system and investigates the main factors contributing to the ductile response of CFS walls. That is in order to suggest improvements so that the shear steel walls respond plastically with a significant drift and without any risk of brittle failure, such as connection failure or stud buckling. A discussion on the calculated response factors in comparison to those suggested in the relevant codes of practice is also presented. [Copyright &y& Elsevier]

Abstract: Non-linear finite element analyses were carried out to evaluate and optimize the seismic characteristics of knee-braced cold formed steel shear walls using software ANSYS. Different structural characteristics including: material nonlinearity, geometric imperfection, residual stresses and perforations are taken into account. The numerical models were verified based on experimental tests. Agreement of the numerical simulations and the test results showed that finite element analysis can be used effectively to predict the ultimate capacity of knee-braced CFS shear panels. A total of 12 models with a various ranges of knee-elements'' lengths were investigated. Of particular interests were the specimens'' maximum lateral load capacity and deformation behavior in addition to a rational estimation of the seismic response modification factor. Preliminary conclusions presented in this paper, refer to the optimum seismic characteristics of knee-braced CFS shear walls and the corresponding dimensions and configuration. [Copyright &y& Elsevier]