Proposed Stiffener Spacing Requirements for the Seismic Design of Short Links in Eccentrically Braced Steel Frames

Abstract

Links in eccentrically braced frames (EBFs) are designed with transverse web stiffeners to achieve the desired seismic performance targets established in current design standards. Prior studies have suggested that stiffener spacing requirements in the standards may be conservative. This paper proposes new stiffener spacing design requirements for short EBF links. The proposed limits were established on the basis of a methodology that combines a numerical solution of the classical problem of inelastic plate buckling of a thick plate under shear thrusts along with comparisons with available experimental data. The resultant design equation was verified through complementary continuum finite-element simulations of 18 wide-flange short links under symmetric cyclic loading. The finite-element simulations suggested that the proposed design equation reduce the stiffener requirements by about 35%, on average, relative to the current stiffener spacing requirements for short EBF links. Limitations and suggestions of future work are discussed.