Ductility in Timber Structures: Investigations on Over-Strength Factors

This paper presents a study on the implementation of connection ductility in timber structures. Regardless for which purpose ductility in timber structures is needed, it is necessary to avoid a brittle failure of the timber element before the ductile element is in the stage of yielding. An over-strength factor is introduced to consider the required distance of the load-bearing resistance of the beam element from the introduced bending moment initiated by the load-carrying capacity of the fasteners. Hence, a Monte-Carlo simulation was conducted, focusing particularly on the scattering of the material properties to determine a reliability index of a joint loaded in bending. Since the reliability index is based on the application of the ductility, a range of over-strength factors is given for different reliability indices. The Monte-Carlo simulation is based on the mean material properties of the experimental specimens. The experiments are explained and the non-linear behaviour is displayed not only for connections loaded in tension but also for joints loaded in bending.