According to modern seismic codes, in concentrically braced frames the seismic input energy should be dissipated by means of the hysteretic behaviour of braces while all the other members (i.e. beams and columns) have to remain elastic. Accordingly, the design internal forces of braces are determined in these codes by elastic analysis of the structure subjected to seismic forces obtained by the...

Among the existing passive energy dampers, I-shaped shear dampers had shown suitable performance in experimental and numerical studies. Although they improve dissipating ductility of concentrically braced frames (CBFs), reduce stiffness ultimate strength system. Three approaches are generally used to overcome problem, including (a) increasing thinness plates, (b) number (c) using more bays. The...

conventional methods for seismic design of structures are based on building capacity. because of the disadvantages of conventional methods, base isolation system  is known as an effective solution to protect structures against earthquakes. in this study the operation of 2-storey steel frame with and without seismic isolators under near-fault earthquake of chichi، northridge and  capemendocine  ...

The objective of this review to be submitted in two independent parts, for steel frames and for RC frames, is to compare their structural performance with respect to the proposed N2-method, and so also of the consequent convenience of using pushover methodology for the seismic analysis of these structures. A preliminary investigation is presented on a pushover analysis used for the seismic perf...

Seismic excitation can cause significant energy to be released within structures. By using special devices, this consumed and dissipated without deforming structural members significantly. Due this, damage is minimized, casualties are prevented during earthquakes, structures extended in their useful life. Over the past five decades, it has been widely acknowledged that steel yielding dampers am...

the present study assesses the seismic performance of steel moment resisting frames (smfs) retrofitted with different bracing systems. two structural configurations were utilized: ordinary concentrically braces (ocbfs), buckling-restrained braces (brbfs). a 7-story and 18-story steel perimeter smfs were designed with insufficient lateral stiffness to satisfy code drift limitations in high seism...

the most conventional method for lateral bracing of steel frames is using diagonal and x steel braces. in conventional method, braces of frame emplace in one bay or more, relative to structural requirement, from first to last story without displace the braces emplacement on height as columnar form. this pattern is a preliminary and simplest bracing template that the generally codes present base...

In United States design practice, three system performance factors (R, Cd, and o) characterize the inelastic behavior of structures and are a crucial component of common elastic design methodologies. However, for steel-concrete composite frame systems these factors have been selected based on comparisons to more traditional and well-studied reinforced concrete and structural steel frame system...