Advancements in the Seismic Design of Cold-formed Steel Structures Through the Investigation of Diaphragm Behaviour and the Influence of Non-structural Components

Download or read book Advancements in the Seismic Design of Cold-formed Steel Structures Through the Investigation of Diaphragm Behaviour and the Influence of Non-structural Components written by Violetta Nikolaidou and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Recent shake table experimental work revealed that cold-formed steel (CFS) buildings exhibit excellent structural performance under high earthquake excitations; however, due to the complex nonlinear response of CFS members and their interactions, the reasons behind this performance are still unclear. Currently, in the AISI S400 North American Standard for Seismic Design of Cold-Formed Steel Structural Systems the seismic design of CFS framed structures is based on the lateral response of CFS framed shear walls and special moment frames, as the primary lateral load resisting elements; the contribution to the lateral stiffness of non-structural gypsum sheathing is included with limitations about its applicability while of the diaphragm component is not taken into account.An experimental diaphragm program of OSB sheathed / CFS framed diaphragm configurations was launched at McGill University. Experimental results underlined the dependency of the diaphragm's lateral response on screw spacing and size and the beneficial effect of panel edge blocking. Diaphragm configurations with non-structural components were also tested. Subsequently, a 3D numerical model of a case-study two-storey CFS building was created incorporating non-structural components. Response history dynamic analyses results revealed the addition of gypsum sheathing and gravity walls as substantially increasing the lateral resistance of the structure. Focusing on the influence of the diaphragm's flexibility on a CFS building a parametric numerical study was realized, where three diaphragm stiffness conditions were examined; flexible, semi-rigid and rigid. Response history analyses results revealed reduction of the wall-line storey drifts with increase of the diaphragm flexibility; the level of that reduction is dependent on the input ground motion. The rigid diaphragm assumption for the building, used in design, was able to capture adequately the shear wall forces; however, it overestimated the wall-line storey drift ratios of the CFS building." --