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...

This paper presents a practical methodology for optimization of concentrically braced steel frames subjected to forward directivity near-fault ground motions, based on the concept of uniform deformation theory. This is performed by gradually shifting inefficient material from strong parts of the structure to the weak areas until a state of uniform deformation is achieved. In this regard, to ove...

Existing literature suggests that substituting mineral aggregates with tire-derived aggregate (TDA) in concrete increases the ductility and toughness of at cost lowering its strength stiffness. Hence, TDA has applications dynamic systems, such as lateral resisting frames sustaining seismic loads. This study investigated application buckling-restrained braced (BRBFs). Buckling-restrained brace (...

Controlled rocking steel braced frames (CRSBFs) are modern systems for resilient building structures known their effective energy dissipation and self-centering features. In a CRSBF, post-tensioned (PT) strands shear fuses the distinct features providing mechanisms. As relatively new structural system, there is need to study this system’s optimal design. Control co-design has gained interest in...

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...

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...

This paper presents a simplified approach for the design of semi-continuous composite beams in braced frames, where specific attention is given to the effect of joint rotational stiffness. A simple composite beam model is proposed incorporating the effects of semi-rigid end connections and the non-prismatic properties of a 'cracked' steel-concrete beam. This beam model is extended to a sub-fram...