Estimation of Behavior Coefficient of steel eccentrically braced frames (EBFs) under Near-fault Pulse-type Earthquakes using Particle Swarm algorithm
Subject Areas : Analysis of Structure and Earthquake
Seyed Abdonnabi Razavi
1
,
Navid Siahpolo
2
,
Mehdi Mahdavi Adeli
3
1 - Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran
2 - Department of Civil Engineering, ACECR institute for higher education, Khouzestan branch, Ahvaz,, Iran
3 - Department of Civil Engineering, Shoushtar
Branch, Islamic Azad University, Shoushtar
, Iran
Keywords: Particle Swarm Optimization (PSO), behavior coefficient, Eccentric braced frame (EBF), Pulse-type near-fault earthquake,
Abstract :
Elastic analysis of structures creates basic shearing forces and stresses that are significantly larger than the actual responses of the structures. By entering the inelastic domain, the structure can absorb and resist a large amount of earthquake energy. On the other hand, nonlinear analysis of structures requires time-consuming and voluminous computational operations, so in most of the codes, a simple and appropriate method called equivalent static method is presented to achieve a reasonable answer to the nonlinear behavior of the structure (without performing a nonlinear analysis). Therefore, due to the importance of ductility in the absorption of seismic energy, the computational forces caused by the earthquake are reduced by introducing the coefficient of structural behavior, R. In this paper, an extensive database consisting of 12,960 eccentrically braced frame (EBF) structures with varying story numbers of 3, 6, 9, 12, 15 and 20, three types of column stiffness and three degrees of bracing slenderness was designed and analyzed under 20 near-faults pulse-like earthquakes. To generate the estimated relation R, 6769 data were interpreted using particle swarm algorithm. The results of a correlation of 0.86 in the test data presented the accuracy of the proposed relation.
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