Evaluation and Comparison of the Seismic Performance of Modern Concentrically Braces in the Near-Fault Zone

Abstract

Abstract Passive control is one of the most common methods to improve seismic performance of the structure. Types of concentrically braces, such as Cross, Knee, and Reverse V, are the most common systems used in steel structures. Choosing the right bracing system for the structure and increasing its efficiency will increase the performance level of the structure. The importance of the bracing system in the near-fault area is very important, considering the magnitude of the earthquake. Therefore, in the current research, 5-story steel structures with X, Knee, Inverted V and Rhombus bracing systems has been modelled with Sap2000 software. The steel structures were subjected to the Kobe earthquake for 10 seconds, in the near-fault area, with the modal time history dynamic analysis method. Nine seismic parameters including Story Displacement, Acceleration, Modal Damping Energy, Base Shear, Shear Force in Beam, Bending Moment in Beam, Shear Force in Column and Axial Force in Column were investigated. The results showed that the X bracing system has the best performance in all parameters, except for axial and shear force in the column. Also, the KBF brace has the weakest performance in all parameters. The average value of the nine parameters in the superior bracing system and the weaker bracing system (KBF) is equal to 98.56%.