Cyclic performance of pre-engineered beam-column connections for mass timber and hybrid mass timber-steel structures

Pre-engineered hanger connections are commonly used as beam-column connections in the gravity load carrying system of mass timber or hybrid timber-steel structures. While these connections are relied upon to transfer shear forces, they must also have sufficient rotation capacity to withstand a design-level earthquake without losing their load-carrying capacities. This study investigates the rotation capacities of two commonly used pre-engineered beam-column connections, including a bolt and collar style connection as well as an interlocking jaw connection. The influence of several parameters on the cyclic performance of the connectors are investigated, including the influence of gravity load, screw configuration, and the installation of two connectors side-by-side on the beam and column face. Furthermore, the cyclic behaviour of a series of connections with a steel column investigating the influence of weld configuration are also presented. Results of the study demonstrate that the bolt and collar consistently achieved maximum rotation capacity beyond 0.06 rad prior to losing their shear carrying capacity while the interlocking jaw connections achieved rotations above 0.08 rad without losing their shear carrying capacity. Placing two connectors in parallel did not change the rotation capacity of the connector. The weld configuration in timber-steel connections had an influence on rotational stiffness and maximum rotation capacity. Ultimately, all the tested connections met the rotation required to meet North American lateral drift limits. • Experiments on pre-engineered timber and timber-steel beam-column connections conducted under combined shear and cyclic rotation. • Influence of connection type, gravity loading, screw configuration, and multiple connectors placed side-by-side studied. • Interlocking jaw (Megant 430 ×150) and bolt and collar (Ricon 390 ×80) achieved maximum rotations beyond 0.06 rad. • Placing multiple bolt and collar connectors side-by-side on the beam/column face does not influence rotation capacity. • Welded bolt and collar connections achieved significant rotation capacities (>0.07 rad) but depends on weld configuration.