Dynamic stiffness and damping of dowel-type connections for timber structures under service conditions

When a dowel-type joint is part of a vibrating system, the connecters exert cycles of load on the timber in embedment at various angles to the grain. Where timber is used in long, tall and light structures, the dynamic response to wind load and human-induced vibration can be critical and joints contribute significantly, in terms of damping and stiffness, to the way the structure as a whole behaves. An experimental study is presented here into the behaviour of timber subject to embedment perpendicular to the grain by a dowel-type connector. It examines the energy dissipation and dynamic stiffness in a single dowel embedding into a tight-fitting half-hole in a piece of Douglas Fir softwood. Its conclusions give an insight into the behaviour under dynamic service loads of this basic element of a dowel-type connection. This work contributes to a more thorough understanding of the damping and stiffness characteristics of timber, which can lead to more accurate estimation of the dynamic response of timber structures.