Concentrically Braced Frames: European vs. North American Seismic Design Provisions
نویسنده
چکیده
A critical review of seismic design provisions for concentrically braced frames (CBFs) in both European and North American (i.e. US and Canadian) codes is presented in this paper. Indeed, even though those codes are based on capacity design philosophy, different requirements and different approaches are used to guarantee the hierarchy of resistances between dissipative and non-dissipative elements, thus leading different overall seismic performance. In detail, the main issues critically discussed are (i) the ductility classes and the correlated force-reduction factors; (ii) the structural analysis methods permitted by different codes; (iii) the modelling aspects of braces; (iv) the detailing rules for both dissipative (bracing members) and non-dissipative elements. Synoptic tables summarizing the corresponding assumptions and requirements in different codes are provided.
منابع مشابه
Evaluating Response Modification Factors of Concentrically Braced and Special Moment Steel Frames in Duplex Buildings
Response modification factor (R-factor) is one of the seismic design parameters to consider nonlinear performance of building structures during strong earthquake. Relying on this, many seismic design codes led to reduce earthquake loads imposed to the structure. The present paper tries to evaluate the R-factors of conventional concentric braced frames (CBFs) and special moment frames (MRFs) in ...
متن کاملEnergy Dissipation of Compression Members in Concentrically Braced Frames: Review of Experimental Data
Design and detailing requirements of seismic provisions for concentrically braced frames ~CBF! were specified based on the premise that bracing members with low KL /r and b / t will have superior seismic performance. However, relatively few tests investigate the cyclic behavior of CBF. It is legitimate to question whether the compression member of CBF plays as significant a role as what has bee...
متن کاملSeismic Behavior of Asymmetric Two-Story X-braced Frames
Concentrically braced frames (CBFs) are one of the efficient lateral load resisting systems in high seismicity regions. One of the common problems with the use of concentrically braced frames is limitation in the architectural application and position of the openings. Two-story X braced frames have more advantages than other configurations of concentrically braced frames, since in many cases th...
متن کاملOPTIMUM PERFORMANCE-BASED DESIGN OF CONCENTRICALLY BRACED STEEL FRAMES SUBJECTED TO NEAR-FAULT GROUND MOTION EXCITATIONS
This paper presents a practical methodology for optimization of concentrically braced steel frames subjected to forward directivity near-fault ground motions, based on the concept of uniform deformation theory. This is performed by gradually shifting inefficient material from strong parts of the structure to the weak areas until a state of uniform deformation is achieved. In this regard, to ove...
متن کاملA simplified model for seismic response prediction of concentrically braced frames
This paper proposes a simplified analytical model for seismic response prediction of concentrically braced frames. In the proposed approach, a multistory frame model is reduced to an equivalent shear-building one by performing a static pushover analysis. The conventional shear-building model has been improved by introducing supplementary springs to account for flexural displacements in addition...
متن کامل