Techno Press
Techno Press

Earthquakes and Structures   Volume 15, Number 6, December 2018, pages 667-685
DOI: http://dx.doi.org/10.12989/eas.2018.15.6.667
 
Seismic behavior of K-type eccentrically braced frames with high strength steel based on PBSD method
Shen Li, Chao-yu Wang, Xiao-lei Li, Zheng Jian and Jian-bo Tian

 
Abstract     [Full Text]
    In eccentrically braced steel frames (EBFs), the links are fuse members which enter inelastic phase before other structure members and dissipate the seismic energy. Based on the force-based seismic design method, damages and plastic deformations are limited to the links, and the main structure members are required tremendous sizes to ensure elastic with limited or no damage. Force-based seismic design method is very common and is found in most design codes, it is unable to determine the inelastic response of the structure and the damages of the members. Nowadays, methods of seismic design are emphasizing more on performance-based seismic design concept to have a more realistic assessment of the inelastic response of the structure. Links use ordinary steel Q345 (the nominal yielding strength fy>=345 MPa) while other members use high strength steel (Q460 fy>=460 MPa or Q690 fy>=690 MPa) in eccentrically braced frames with high strength steel combination (HSS-EBFs). The application of high strength steels brings out many advantages, including higher safety ensured by higher strength in elastic state, better economy which results from the smaller member size and structural weight as well as the corresponding welding work, and most importantly, the application of high strength steel in seismic fortification zone, which is helpful to popularize the extensive use of high strength steel. In order to comparison seismic behavior between HSS-EBFs and ordinary EBFs, on the basis of experimental study, four structures with 5, 10, 15 and 20 stories were designed by PBSD method for HSS-EBFs and ordinary EBFs. Nonlinear static and dynamic analysis is applied to all designs. The loading capacity, lateral stiffness, ductility and story drifts and failure mode under rare earthquake of the designs are compared. Analyses results indicated that HSS-EBFs have similar loading capacity with ordinary EBFs while the lateral stiffness and ductility of HSS-EBFs is lower than that of EBFs. HSS-EBFs and ordinary EBFs designed by PBSD method have the similar failure mode and story drift distribution under rare earthquake, the steel weight of HSS-EBFs is 10%-15% lower than ordinary EBFs resulting in good economic efficiency.
 
Key Words
    Eccentrically Braced Frames (EBFs); high strength steel; performance-based seismic design (PBSD); story drifts; failure mode
 
Address
Shen Li, Chao-yu Wang, Xiao-lei Li: School of Civil Engineering and architecture, Xi\'an University of Technology, Xi\'an 710048, China
Zheng Jian, Jian-bo Tian: State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area, Xi\'an University of Technology, Xi\'an 710048, China
 

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