عنوان مقاله [English]
Steel plate shear walls are categorized as one the seismic bearing systems in steel structures in earthquake prone areas. Although steel plate shear walls are used to resist lateral loads in recent decades, its complex behavior has brought difficulties in employing this system. In this study, the lateral behavior of un-stiffened steel plate shear walls is investigated via nonlinear static analysis (i.e. pushover analysis). Three different special steel moment frames having 1, 5 and 10 stories is designed based on the codes criteria. Then, the finite element models incorporating both the plastic behavior of steel material and large displacement of the steel plate due to buckling is developed as exact models. In addition, simplified equivalent strip models are created as the more practical code-based approach of modeling for comparison against the exact method. The effects of different parameters including applying gravitational loads, the lateral loads distribution pattern, modeling technique and rectangular opening in shear wall panel are evaluated. Results of the analyses show that in monotonic loading, the strip model yields results similar to those of the more rigorous finite element model but in much less time. Also, it is observed that use of the design method promoted by the design code, results in the plastic hinges to be formed first in the columns instead of walls. When the wall contains rectangular openings, it is shown that they must be accompanied with perimeter stiffeners on the edges of the opening. Otherwise, a large stress concentration would occur at the corners of the opening. Even with the peripheral stiffeners, presence of an opening decreases the lateral stiffness and strength of the wall system more or less linearly with regard to variation of the opening size. Eventually, semi-analytical relations are proposed to estimate the lateral stiffness and strength reduction due to the presence of an opening.