2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Petr Sejkot, Kolkner Institute
Typical connections in wood structures consist of structural members connected with thin-walled steel elements, commonly angle brackets. The design of these steel elements is typically based on short-term load bearing capacity experimental testing. Experiences from the experimental testing indicate that both steel plate and connectors possess properties such that these connections can be designed to behave in ductile manner. Following the capacity design principle, during seismic loading the structural members remain undamaged while the damage and most of the energy dissipation is confined within the steel elements. However, there is insufficient support in Building Design Codes to design any building for a seismic situation in such a manner. This paper presents development of numerical models of the connections and subsequent validation by experimental results. Their applications in replicating performance of a number of metal bracketed connections with these characteristics are illustrated. Two sources of ductility for the overall arrangement, namely deformations in the metal connectors and in nails (bending and pulling out) due to cyclic loading have been identified. The steel plate absorbs significantly less energy after the first circle while the nails can dissipate energy more consistently over the cycles, characterized by pinching and elasto-plastic behavior respectively. The models offer insights into detailing ductile connections in wood and possibility in the optimization of the connectors for seismic design.