Impact of the Surface Quality of a Drilling On the Cyclic Behaviour of Wood for a Dowel-Type Assembly

The whole vibration behaviour of a wooden building is partly governed by the assemblies. As non-linearity is a characteristic of rod-type connectors, this behaviour is thus transposed to the building. Among rod-type assemblies, the dowel-type assembly allows smooth rod connections with a metal plate inserted into the wood. This type of assembly transmits forces between two wooden elements by shearing the dowels. Energy dissipation is possible thanks to the plasticization of dowels and the wood in contact with the dowel. The contact zone is an important part of the transfer of loads but also for dissipation. The present work focuses on the impact of the surface condition (following drilling) of the wood on the hysteretic behaviour of the assembly. For the experiments, half-drilled samples are tested applying cyclic compressive loadings without bending of the dowels. The drilling process of the samples applied helps reduce variability on the wood. To clearly visualize the different behaviours, the scaled surface after drilling (drilling at high speed and with a worn drill bit) is compared to the non-scaled surface (drilling at moderate speed and with a new drill bit). The results thus obtained show the effect of the surface condition on the mechanical behaviour of the assembly, whether in terms of stiffness or energy dissipation. The assembly with the scaled surfaces dissipated more energy for a given force, which would suggest that the use of a softer material at the interface between the dowel and wood would allow more dissipation, however the stiffness would be strongly impacted.