Thesis (Ph.D.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

The aim of this thesis is to study the cold formed steel )CFS( shear wall under horizontal loads. To perform this study, three main research points are considered. The first part is the buckling strength of the chord studs that are commonly made of built up I-section. Built-up I-sections are presented using a numerical finite element analysis for the calculation of axial strength of cold formed steel built-up I-sections composed of two back-to-back channels or stiffened web sigma (V). The results of the parametric study state that the design specification noted in the AISI are generally conservative for long and medium length columns, but may give un-conservative estimates for some of the short columns.The second part of the thesis is the study of the steel braced CFS shear walls .Braced CFS shear walls are presented using a verified finite element method that represents the full scale braced shear walls under seismic loads and to study their ductility. A parametric study is performed to investigate the Response Modification Factor (R) of the CFS braced shear-walls. The parametric study showed that the North American Specification is about 20% conservative in estimating the (R) Factor.The third part of this thesis concerned in the sheathed CFS shear walls. In this part, a new type of CFS shear wall that are sheathed with Ferro-cement reinforced Boards is studied experimentally and analytically. Finite Element (FE) model is generated to simulate the experimental work. The model showed an accurate estimation for the experimental results of the ultimate load and stiffness. The FE model is applied on different sheathing material tested by other researchers and also gave accurate results.The whole study of the sheathed CFS shear walls showed that, Compared to sheathed Gypsum, OSB or Braced shear walls,the Ferro-cement boards are also a very reliable sheathing material with a good serviceability limit under horizontal loads

Issued also as CD