Characterization of a dovetail joint for timber roofs

In this paper experimental and numerical analyses on dovetail joints for timber roofs are presented. These joints have a ordinary shape and are an old efficient type of connection, but they have become economically advantageous in the last years because the progress on machine tools. In literature there are few information and no design rules for the dovetail joint, as well as in Eurocode 5 and in other design guidelines. The results of shear tests on the joints are presented. Several variables were taken into account in order to characterize the connection, in particular: the angle of the tail, the wood fibre configuration of the tenons and the geometry of the groove. Different failure modes were observed depending on the groove geometry. Based on the experimental results an empirical model was developed in order to describe and design the behaviour of the dovetail joints. Finally, the behaviour of the dovetail joints were analyzed by means of finite element models.