Seismic Behavior of Steel HSS X-Bracing of the Conventional Construction Category

This paper presents the results of an ongoing research project on the seismic performance of concentrically braced steel frames of the Conventional Construction category designed according to NBCC 2010 and CSA-S16 seismic provisions. The braced frames studied are of the tension-compression X-bracing configuration and special attention is devoted to the response of the connection at the brace intersection point. Numerical simulations were performed to determine the inelastic demand on the braces and brace connections. A test program including four full-scale quasistatic cyclic tests was carried out to verify the findings of the numerical simulations. The results indicate that the behaviour of the bracing members is influenced by the type of mid-connection. In particular, connections with single lap splices at the intersection of the braces may be prone to local instability. In all tests, failure occurred in the connections, indicating that more attention must be paid in design to prevent premature and brittle failure in connections.