Comparison Study of CBFs and EBFs Bracing in Steel Structures with Nonlinear Time History Analysis

Yaseer Khademi,Mehdi Rezaie

doi:10.28991/cej-030945

Abstract

Steel concentrically braced frames (CBFs) and Steel eccentricity braced frames (EBFs) are frequently used as efficient lateral load resisting systems to resist earthquake and wind loads. This paper focuses on high seismic applications where the brace members in CBFs and EBFs dissipate energy through repeated cycles of buckling and yielding. The present study evaluates in detail the design philosophies and provisions used in the United States for these systems. The results of a total of 176 analysis of nonlinear history of seismic behavior of CBFs and EBFs braces have been presented. Notable differences are observed between the performances of the CBFs and EBFs designed using American provisions. The similarities and differences are thoroughly discussed.

Highlights

Moment resisting frames, concentrically braced frames, eccentrically braced frames, knee braced frames steel plate shear, and zipper braced frames are being commonly used as lateral force resisting systems for steel structures
The paper has explored in detail the similarities and differences between the seismic behaviors of steel concentrically braced frames (CBFs) and eccentrically braced¬ frames (EBFs) designed to the provisions of AISC341 developed in the United States
In comparison, the stress of columns US-EBF and US-V shows that in lower storys, US-EBF braced columns are more than US-V frames and As the height increases in the structures, the amount of stress in the columns increases from US-V to US-EBF

Summary

Introduction

Moment resisting frames, concentrically braced frames, eccentrically braced frames, knee braced frames steel plate shear, and zipper braced frames are being commonly used as lateral (i.e. seismic and wind) force resisting systems for steel structures. While new systems such as buckling restrained braced frames are gaining popularity, Moment resisting frames (MRFs) and concentrically braced frames (CBFs) are considered as two of the most popular systems among these alternatives. The 2011 Christchurch earthquake in New Zealand resulted in fracture of several eccentrically braced¬ frames (EBFs), further adding to the popularity of CBFs

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Conclusion