Seismic Design of Buckling Restrained Braced Frames Using European and Japanese Approaches

Abstract Since original development of buckling restrained braces in Japan in 1970's, they were extensively studied worldwide. In comparison with conventional braces, buckling restrained braces provide a quasi‐symmetrical cyclic response with greatly enhanced ductility and energy dissipation. In Japanese design practice, buckling restrained braces are regarded as supplemental damping devices aiming at enhancing the energy‐dissipation and keeping control of lateral drifts in multi‐storey moment‐resisting frames. Buckling‐restrained braced frames were introduced in US design practice in 1999, regarded as primary lateral load resisting system, designed using conventional force–based approach which relies on a dissipative response, implicitly accepting structural damage under the design seismic action. Such an approach had the main benefit of being familiar to engineers and allowed for an easier adoption in design practice of the new system. The force‐based design of buckling restrained braced frames was later adopted by other codes, such as the new version of the European Standard prEN 1998‐1‐2, currently under revision. This paper presents comparative results of two design methods, as outlined in the AIJ and the second generation of Eurocode 8. A multi‐storey building with steel buckling restrained braced frames placed in a high seismicity area is designed using both approaches, and the seismic performance of the two structures is evaluated through pushover analyses.