Experimental and numerical investigation of stiffened angle connection in a minor axis

The bolted angle connections which are simple, fast, cost-effective, high quality, and no site welding have been recognized as their excellent performance. The moment-rotation behavior of both major and minor axis should be both taken into considering, however, the lack of research on minor axis limits the more comprehensive application. Five monotonic tests were carried out to investigate the influence under different parameters, and a new type connection were considered and detailed. Refined finite element models were built to validate the experimental results and to do several parametric analyses on initial rotational stiffness and plastic moment resistance, including of a presence of stiffened seat angle, angle thickness, and prying force. Furthermore, a new simplified plate method was proposed for calculating stiffness of stiffened angle and web in bending. The stiffened angle gives a significant increase at the moment-resisting capacity and the initial stiffness, the ultimate rotation of all tested specimens was beyond 0.067rad. The initial stiffness and plastic moment resistance of the joints were also controlled by the column web. The presence of the stiffener in the compression zone has the none effect on initial stiffness. The numerical analysis has captured the failure reason for weld and more attention should be paid to welding of stiffener in engineering design and practice. Adding stiffener at the top-and-seat angle joint can reduce the prying force of bolt, but it still cannot be ignored. The theoretical results were in good agreement with the experimental data and finite element results; therefore, it can be used to guide the design and selection of joints.