Cyclic Inelastic Behavior of Plate Welded to Concrete-Filled Circular Hollow Section

An experimental study was conducted to investigate the tensile strength of a gusset plate connected to the steel surface of a Concrete Filled Tube (CFT) segment, as this could be a simple detail appealing when connecting braces to CFT bridge columns in a seismic retrofit perspective (or even for new design). Sixteen specimens were built with various concrete-filled Circular Hollow Section sizes, as well as different thicknesses of the longitudinal gusset plate (a.k.a. branch plate). Monotonic and cyclic tests were performed on these specimens, for which the failure modes and ultimate strength of the connections are presented. The failure strengths from the experiments are compared with the analysis results obtained from finite element models. Results from this comparison are found to generally match with each other. However, hysteretic behavior is found to be deficient and it is recommended to keep this connection elastic if used for seismic design purpose.