Steel-Timber Composite Beam-to-Column Connections with Shear Tab

This paper focuses on the structural behavior and negative bending moment capacity of steel-timber composite (STC) beam-to-column connections with shear tabs. It is hypothesized that timber slabs with relatively high tensile strength acting compositely with steel beams can allow for large negative bending moment resistance despite their being a simple (or pin) connection between the steel beam and column. Four full-scale STC beam-to-column cruciform subassemblies with shear tab connections were fabricated and tested under a monotonically increasing load that produced negative bending moments at the beam-to-column connections. In addition, a steel-concrete composite (SCC) beam-to-column connection with identical geometry to that of the STC joints was fabricated and tested to evaluate the structural performance (stiffness, strength, and ductility) of the STC compared with SCC connections. The main variables in the experimental program were the type of connection (i.e., continuous, spline, and bolted steel plate) between the cross-laminated timber slabs across the column and the depth of the shear tab. Lastly, a simple method inspired by the component-based approach is proposed for estimating the peak load carrying capacity of the STC beam-to-column connections with a shear tab.