| Moment connections containing mechanical fasteners are important components for a timber frame structure to resist seismic loading. There has been limited research on behaviour of timber moment connections under reversed cyclic loading, and most of the models are based on empirical curve fitting of the test data, which requires a large number of joint tests. A few analytical moment-rotation models were developed by previous researchers, but most of the analytical models are only for monotonic loading.; This thesis describes a two-part numerical model for predicting the moment-rotation behaviour of multi-fastener timber joints subjected to reversed cyclic loading. In the first part, an earlier single nailed joint finite element model is modified to be more general, for analysing joints containing other dowel-type fasteners, in which the interactions of axial stress and shear stress in the fastener during yielding are taken into account. In the second part, a multi-fastener moment joint model is developed. This model predicts moment-rotation behaviour of a multi-fastener joint based on the load-displacement response for each fastener predicted by the single fastener joint model. In a moment-resisting joint, the load-displacement relationships for fasteners can differ from each other because of the differences in angle between loading and grain direction. The grain angle effect on the load-embedment response of a single fastener bearing on wood is modelled as a three dimensional empirical surface.; The numerical model was verified by full size joint testing. A comparison between the theoretical and experimental results shows that the mathematical model predicts the moment-rotation behaviour of multi-fastener joints with good accuracy. |
