Structural performance of nailed bamboo plywood plate connectors in laminated bamboo lumber assemblies

Connections serve a key function in determining the structural performance of laminated bamboo lumber (LBL) truss systems, as their mechanical behavior directly influences shear resistance, in-plane stiffness, ductility, and energy dissipation. Metal-plate connectors (MPCs) in LBL trusses are prone to brittle failure as a result of inadequate anchoring, thereby undermining their structural reliability. This analysis proposes a connection system for LBL trusses, termed the Nailed Bamboo Plywood Plate Connector (NBPC), which integrates bamboo plywood (BP) and power-driven nails. Experiments on 180 NBPC specimens were conducted to evaluate the effects of end distance, center-to-center spacing, and the presence of a reinforced adhesive layer under the monotonic lateral resistance of the connections. The results indicate that failure modes are highly dependent on geometric configurations, with typical failures including BP shear failure, nail withdrawal, and nail shearing. Specimens with adhesive reinforcement exhibited markedly enhanced lateral load capacity and stiffness compared to those without adhesive. Design recommendations are provided to mitigate the premature splitting of the bamboo plywood. A modified theoretical equation, based on an ideal elastoplastic assumption, was derived and validated through experimental data, yielding prediction errors below 10 %. Moreover, a two-stage analytical model based on Hassanieh's framework was developed, accurately reproducing the load-displacement responses of adhesive-reinforced specimens. This research establishes both theoretical and experimental foundations for the structural application of NBPCs in LBL assemblies, offering a viable solution for engineered bamboo connections.