Experimental Performance of Long Links in Eccentrically Braced Frames

Abstract

Short, shear yielding links are preferred in eccentrically braced frames (EBFs) because of their demonstrated excellent strength, stiffness, and energy‐dissipation capacity. Longer flexural yielding links, however, can offer important architectural advantages and have been used in a number of recently constructed EBFs. An experimental investigation was conducted on EBF subassemblages constructed with long links attached to columns. The dominant failure mode was fracture of the link flange at the link‐to‐column connection. These connection failures occurred at levels of inelastic rotation that do not appear adequate for application in severe Seismic environments. Based on this experimental program, it is recommended that long links attached to columns should not be used in EBFs. There is no evidence from this test program that long links cannot be used when located within a span between two braces, although short links are still preferred for best structural performance. The investigation also demonstrated the potential for instability in the beam segment outside of the link, and the resulting loss of EBF strength and ductility.