Cyclic Testing of Pre-engineered Beam-Hanger Connections & Reinforcement of Holes in Glulam Beams Using Self-tapping Screws

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Vojtila, Gabriella
Connections , Wood , Earthquake , Glulam , Glued-Laminated Timber , Self-Tapping Screw , Cyclic
This thesis is split into two sections: the first evaluates the performance of pre-engineered beam-hanger connections under cyclic loading, and the second evaluates the reinforcement of holes in glulam beams using self-tapping screws. Chapter 3 describes laboratory testing of the Megant 430x150x50 beam-hanger connector under applied interstorey drift deflections based on a modified version of the CUREE loading protocol. The performance of the Megant 430x150x50 connector was evaluated and it was determined that the connector surpassed interstorey drift limits of 2.5%, outlined in the 2015 National Building Code of Canada. The failure of the connector was due to a combined tension and pull-out failure of the wood screws. It was observed that the gravity load has a significant effect on the interstorey drift capacity and energy dissipation by the connector. Chapter 4 describes experimental tests conducted on different size glulam beams: 6-layer, 9-layer and 11-layer. Each beam is tested under three test configurations: no hole, a 2-inch hole at ¼ span and a reinforced 2-inch hole at ¼ span. It was determined that when a hole is introduced, the overall strength capacity of the beam decreases. When self-tapping screws are used as reinforcement around the hole, the strength capacity of the beam can increase up to 34.4% compared to a hole with no reinforcement, and can even over-reinforce the beam by 6.2%, as seen in the 9-layer beam, when compared to its reference beam. The depth-to-span and diameter-to-depth of beam (d/h) ratios have a large impact on the strength and behavior of the beam.
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