This paper deals with simple portal or gable steel frames with varying moment of inertia. Critical load for such frames is calculated by means of a very simple and approximate method through which the variation of moment of inertia for the members is considered by a quadratic function and then the equilibrium and continuity conditions have been used. The degree of precision of this method has b...

The main aim of the present study is to optimize steel moment frames in the framework of performance-based design and to assess the seismic collapse capacity of the optimal structures. In the first phase of this study, four well-known metaheuristic algorithms are employed to achieve the optimization task. In the second phase, the seismic collapse safety of the obtained optimal designs is evalua...

Nowadays, many buildings with steel Moment Resisting Frames (MRF) are built in seismic zones when seismic codes are at its early stages of development, and as such, these structures are often designed solely to resist lateral wind loads without providing an overall ductile mechanism. On the other hand, current seismic design criteria based on hierarchy of resistance allow enhancing the structur...

Hybrid moment frame come together with reinforced concrete columns with structural steel beams (RCS). This Composite system provides several key advantages over current steel or concrete moment resisting frame. Past studies have shown this system to be efficient in both design and building stage while able to keep sufficient strength and necessary ductility in seismic zone.Although past researc...

in this paper, moment-curvature behavior and ductility of prestressed concrete members based on nonlinear analysis is investigated. influence of various design parameters on ductility of flexural members is determined according to appropriate materials models for stress-strain curves of concrete, prestressing steel and conventional reinforcements. parameters studied include reinforcing index (ω...

Modeling buildings response to blast and subsequent progressive collapse interested more and more researchers during the past two decades. Due to the threat from extreme loading, efforts have been made to develop methods of structural analysis and design. In this paper, progressive collapse capacity of steel moment frames was first investigated using alternate load path method, then a nonlinear...

Due to lack of the proper and well behavior of steel moment-resisting connections subjected to the great and major earthquakes, excessive researches have been conducted to mitigate the damages on the primary elements and connections. Therefore, elimination of residual drift and increasing the plastic rotation capacity for the connectors in the panel zone are required. The main purpose of this s...

in the aftermath of the 1994 northridge, california, earthquake. a significant number of steel moment resisting structural systems were damaged. many studies and researches have been conducted to improve the seismic performance of structures after the catastrophe. one of the proposed connections for special moment-resisting frames included aisc-358 is kaiser bolted bracket moment connection, br...

The behavior of corroded steel–concrete composite beams under hogging moment was studied by experimental investigation and theoretical analysis. A total of eight specimens, six of which had corroded shear studs, were tested. The corrosion rate of studs ranged from 0 to approximately 50%. The constant-current accelerated corrosion method was adopted to accelerate the corrosion process. The loadi...

This work represents an effort to develop one plausible realization of the effects of the scenario event on tall steel moment-frame buildings. We have used the simulated ground motions with three-dimensional nonlinear finite element models of three buildings in the 20-story class to simulate structural responses at 784 analysis sites spaced at approximately 4 km throughout the San Fernando Vall...