Experimental study on the traditional timber mortise-tenon joints

The inverted-trapezoid sectioned dovetail (ITSD) mortise-tenon joint was popular during the Chinese Song Dynasty. To investigate the particular features of the ancient wood joint, three 1:4 scaled models of a double-span timber frame with two exterior joints and an interior joint were fabricated according to the construction method commonly used in Chinese traditional wood structures, and tested subjected to fully reversed cyclic loading. Investigated were the mechanical properties of the ITSD mortise-tenon joints such as the connection stiffness and flexibility, hysteretic model and the relationship between the bending moment and relative rotation (i.e. the M-θ ' model). The constitutive parameters of the Kishi-Chen M-θ ' model for ITSD mortisetenon joints were calibrated using statistical fitting methods. Besides, an assumption applicable to the connection type (e.g. pinned, semi-rigid or rigid joint) at a given connection bending-moment level was suggested with respect to practical engineering purposes. Furthermore, the M-θ ' model obtained for ITSD mortis-tenon joints was incorporated into the commercial software SAP2000, and the experimental hysteretic curves obtained for the three scaled specimens were compared with the curves obtained using finite element method (FEM), it was found that the M-θ ' model validated by this study was applicable to the ITSD mortise-tenon joint.