Parametric study and computation of seismic performance factors of braced shear panels

By locating a steel shear panel at the intersection point of the X-braces, concentrically or eccentrically braced shear panel (CBFSP and EBFSP) is formed. In this paper, to perform parametric study, 1-story CBFSP and EBFSP models with span length greater or less than height are considered. Using linear static analyses, the effects of size and location of the shear panel on the lateral stiffness of the frame with respect to the moment resisting frame with the same member sections are investigated. Next, for 1- and 3-story models, maximum displacement along with base shear and the ratio between the dissipated energy and input energy are examined under 4 ground motion records. Behavior of the truss elements in cross-strip model for nonlinear dynamic analyses is validated based on a performed experimental program. The findings show that the optimum state is achieved by decreasing size of the shear panel and situating it at the middle of the frame or to some extent upper. Furthermore, in this study, tentative values of the over-strength, deflection amplification and response modification factors, which are estimated by pushover curves, are proposed. Using linear regression, an equation is obtained for estimation of the fundamental period of CBFSP and EBFSP.