This paper reviews selected recent innovations that expand the range of applicability of a number of new and emerging structural steel systems that can provide effective seismic performance. Focus is on recent developments on: (a) Steel Plate Shear Walls having light gauge infill plates; (b) Perforated Steel Plate Shear Walls; (c) Buckling Restrained Braced frames designed to meet Structural Fu...

from the time that civil engineers have used steel in building structures, they tried to increase its strength so as to produce more economic and lighter structures by using more elegant sections. increase of steel strength is not always useful for all members of a steel structure. in some members under certain conditions, it is needed to reduce the strength as much as possible to improve the b...

in this study, for evaluating ductility of ordinary concentrically braced frames (ocbfs) and special concentrically braced frames (scbfs) which are x- braced in two adjacent middle spans, 16 steel ordinary concentrically braced frames and 16 special concentrically braced frames are studied. the results confirm that, although most of ordinary concentrically braced frames, which are x-braced, can...

Buckling-Restrained Braced Frame system(BRBFs) are a new type of steel seismic-load-resisting system that has found use in several countries because of its efficiency and its promise of seismic performance far superior to that of conventional braced frames. The system is addressed in the 2005 edition of the AISC Seismic Provisions for Structural Steel Buildings, also a set of design provisions ...

the rotational friction dampers can be improved the seismic behavior of the steel structures, and they can be reduced the internal forces in the bracing members, columns and the other structural members. in this research, a simple method for modeling and analysis of braced frames equipped by these dampers is proposed. the proposed model describes seismic behavior of dampers very well and it is ...

This study is devoted to seismic collapse safety analysis of performance based optimally seismic designed steel chevron braced frame structures. An efficient meta-heuristic algorithm namely, center of mass optimization is utilized to achieve the seismic optimization process. The seismic collapse performance of the optimally designed steel chevron braced frames is assessed by performing incremen...

zipper braced frames are an innovative bracing system for steel structures. conventional inverted-v-braced frames exhibit a design problem arising from the unbalanced vertical force generated by the lower story braces when one of them buckles. this adverse effect can be mitigated by adding zipper columns or vertical members connecting the intersection points of the braces above the first floor....

response modification factor (r-factor) is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake. relying on this, many seismic design codes led to reduce earthquake loads imposed to the structure. the present paper tries to evaluate the r-factors of conventional concentric braced frames (cbfs) and special moment frames (mrfs) in ...

Response modification factors (R-factor) are used in current seismic building codes to reduce earthquake forces associated with seismic design level to determine force levels. In recent years, many authors have shown great interest in the development of seismic structural systems and several theoretical and experimental studies have been conducted to investigate performance of dampers but littl...

In this study, topology optimization is applied to concentrically braced frames in order to find economical solutions for conventional structural steel frames. Differential Evolution Algorithm and Dolphin Echolocation Optimization are applied for structural optimization. Numerical examples are studied and results of comparison with other meta-heuristic algorithms, including Genetic Algorithm, A...