Evaluation of the Interstorey Drift Performance of Timber Beam-Hanger Connection Systems

This paper presents the results of a study on pre-engineered steel and aluminum, bolted-plate (BP), staggered dove-tail (S-DT), and dove-tail prototype (DTP) beam-hanger connection systems for glue-laminated timber joints under a combination of shear and reversed cyclic loading. A total of seven systems were tested to observe the evolution of damage, failure modes, and moment-rotation behaviour. The interstorey drift/deflection of a building that would cause failure of each system is inferred from the ultimate rotation capacities and compared to the limit(s) prescribed by Clause 4.1.8.13.3 of the National Building Code of Canada. The BP systems generally reached an interstorey drift exceeding 2.5%, while the S-DT and DTP systems reached drifts of 0.6% and >1.2%, respectively. The BP systems also exhibited more ductile failure modes than the S-DT and DTP systems, involving withdrawal failure of the wood screws. Recommendations are made for appropriate connectors to use in each building category considered.