%0 Journal Article
%T Analytical Analysis of Seismic Behavior of Cold-Formed Steel Frames with Strap Brace and Sheathings Plates
%A M. Gerami
%A M. Lotfi
%J Advances in Civil Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/535120
%X Cold-formed steel frames (CFS) are popular all over the world. In this study, we have investigated 112 frames with different bracing arrangements and different dimensional ratios with different thicknesses of sheathing plates under cyclic and monotonic loading using Finite Element Nonlinear Analysis. We also evaluated seismic parameters including resistance reduction factor, ductility, and force reduction factor due to ductility for all specimens. On the other hand, we calculated the seismic response modification factor for these systems. The maximum modification factor among shear wall panels with sheathing plates related to GWB (gypsum wall board) specimen with thickness of 15£¿mm was 5.14; among bracing specimens in bilateral bracing mode related to B sample was 3.14. The maximum amount of resistance among the specimens with bilateral (2-side) bracing systems belongs to the specimen C (2-side double X-bracing) with the dimension ratio of 2 (4.8£¿m ¡Á 2.4£¿m) and resistance of 305.60£¿kN and also among the shear wall panels with sheathing plates, it belongs to DFP (douglas fir plywood) with a thickness of 20£¿mm and resistance of 371.34£¿kN. 1. Introduction Nowadays, in many countries, the use of LSF system has been developed due to many advantages including high speed, quality, and suitable seismic performance. This system which is made of steel sections with rolled cold members came into the construction industry in 1946 [1] but its usage was limited due to noneconomic feasibility. Since 1990, LSF systems have been developed extensively for many reasons such as the rising price of wood and its limited supply of resources, environmental problems, the need to fast and mass production of housing, and the necessity of using prefabricated buildings. As today, this system has large usage in the long term and medium term construction of commercial and residential buildings in America, Canada, Australia, Japan, and many other countries [2]. One appropriate strategy to improve the seismic performances of these buildings is the use of structural sheathings or bracings. The bracings transmit the horizontal forces from the floor and ceiling levels to foundation. Zeynalian and Ronagh performed three series of full-scale shear wall tests with aspect ratios of 1£¿:£¿1 or 2£¿:£¿1 and fibre cement boards sheathed panels. Each series consisted of identical wall panels tested using a cyclic loading regime. They reported that the performance of this kind of CFS lateral resistant systems under cyclic loads is satisfactory and can be considered as a reliable system even in high
%U http://www.hindawi.com/journals/ace/2014/535120/