UBC Theses and Dissertations
Timber moment connections using glued-in steel rods Oh, Jiyoon
The experimental study completed in this thesis focused on timber-steel hybrid moment connections using d=12.7mm diameter mild steel threaded rods glued into Douglas-Fir glulam with polyurethane based adhesive. Two phases of experiments were conducted: the first to determine the minimum design parameter values that result in a ductile tensile failure of the glued-in steel rod, instead of a brittle timber or pull-out failure; and the second, to determine a relationship between the different design parameters and the moment capacity of the connection. The work established that the moment connection fails in a ductile manner due to rod yielding and plasticizing, when the shear force induced into the system was less than 25% of the maximum axial capacity of the steel rods. Then, ductile failure occurred even when the edge distances of the steel rods were below the recommendation of a minimum 2.5d to prevent splitting of the wood. Rod pull-out failure was prevented by having a glued-in embedment length of the rods equal to or greater than 15d. In addition, ductility and equivalent viscous damping ratio were found to decrease as the moment capacity of the connection increased. The theoretical yield moment was calculated based on the assumption that the compression and tension members are timber and steel, respectively, and by applying the concept that plane-sections remain plane and the traditional elastic transform theory. The experimentally determined yield moments were established to be a close match. The results of the research provide guidance to practicing engineers to design moment connections with glued-in steel rods.
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Attribution-NonCommercial-NoDerivatives 4.0 International