Cyclic behaviour of concrete filled steel tubular column to steel beam connections

An experimental investigation into the behaviour of composite column-to-beam connections using ten large-scale connections has been conducted, four under monotonic loading and six under cyclic loading. This paper presents the details and results of the six cyclic tests. Details and results from the monotonic tests are reported in a companion paper. All connections consisted of a concrete-filled steel tube (CFST) column (circular), a compact universal beam section and a shop fabricated connection stub. Monotonic testing was first carried out and the results, were used to conduct the cyclic tests. Each specimen tested cyclically had the same general form, consisting of a direct connection of the beam to the tube wall (using flange connection plates, and web cleat plates) and reinforcing bars welded to the top and bottom flanges, embedded into the concrete core. It was found that provided the connection to the face of the column had the capacity to force the hinge into the beam itself, the specimen behaved in a very stable fashion, and achieved ductility levels which were only limited by the beam and the nature of the test itself.