Response of a Novel Beam-to-Column/Brace-to-Frame Connection to Monotonic and Cyclic Shear Loading

A new universal structural joint was developed. While in bending it has a high rotational capacity, which can be accompanied by large bending stiffness and strength, in shear, it also has a very high shear deformation capacity, which can again be accompanied with large shear stiffness and strength. While the former characteristic makes it a good candidate for being used as a beam-to-column joint, the latter makes it highly applicable in connecting braces of a braced frame to the frame members. The experimental study carried out previously on this joint, concentrated on the performance of its steel specimens under ‘monotonic’ shear loading as well as that of its aluminium specimens under both ‘monotonic’ and ‘cyclic’ shear loading. The current study, however, comprises the experimental investigation into the behaviour of the mild steel specimens of this joint under ‘monotonic’ and ‘cyclic’ shear loading. As expected, the monotonic shear loading of the specimens of this new joint resulted in great amount of shear deformation, in contrary to basically all currently-used structural connections which lack any appreciable shear deformation capacity. Moreover, the specimens tested under cyclic shear loading also performed very well. The hysteresis loops of these specimens were ‘stable’ and ‘well-rounded’, implying large amount of energy dissipation in each cycle. Such very ductile response of the connections in shear is expected to be exploited in various circumstances in offshore as well as onshore structures to result in a ductile overall behavior of the structure.