Mehran Zeynalian
University of Isfahan
Iran
Title: Seismic Performance of Cold-Formed steel shear walls
Biography
Biography: Mehran Zeynalian
Abstract
The use of cold formed steel structures has grown dramatically in recent years all over the world but with greater rate of growth in non-seismic regions. Adequate bracing and brace performance is of paramount importance to improve the acceptability of these systems in earthquake prone regions. In this speech, the lateral performance of different configurations of cold-formed steel shear walls will be discussed based on some experimental tests on full scale walls of 2.4 m × 2.4 m under cyclic loading. Also, application of non-linear finite element analyses for investigating the seismic characteristics of the cold formed steel shear walls will be illustrated highlighting different structural characteristics including: material nonlinearity, geometrical imperfection, residual stresses and perforations. Of particular interest are specimens maximum lateral load capacities, load-deformation behavior, and evaluated seismic response modification factors. The speech also looks at the failure modes of the systems 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. In addition, prescribed seismic response modification factors for different CFS configurations by the standards will be examined. It becomes clear that while the suggested R factors in AISI-standard for some configurations are conservative, the values recommended by AS4600 seem to be too low.