Mechanical Properties of Tou Mortise-tenon Joints of the Traditional Timber Buildings in the South Yangtze River Regions

In order to study the structural performance and its influencing factors of the Tou mortise-tenon joints which are widely used in the traditional timber buildings in the South Yangtze River Regions, the failure modes, hysteretic curves, skeleton curves, rotation rigidities of the mortise-tenon joints under low-cycle reversed load were analyzed by the scaled model tests. With the consideration of the nonlinear contact influence of the mortise-tenon joint and the nonlinear stress-strain behavior of the timber material, the mechanical properties of the Tou mortise-tenon joints were analyzed by ANSYS software, and the theoretical results were compared with the experimental ones. The comparison results show that the hysteretic curves of the Tou mortise-tenon joints appear to be Z shaped and have the obvious pinch effects. During the tests, these mortise-tenon joints orderly experience the elastic stage, the yield stage and the failure stage. The failure mode of these joints are the fracture of tenon, and the ultimate rotation angles range from 0.11 to 0.14 rad. The theoretical results agree well with the experimental ones. Finally, the relationship of in-plane rotational rigidity (vertical) KV, out-of-plane rotational rigidity (horizontal) KH and tortional rigidity KR of the Tou mortise-tenon joint was obtained, i.e., KV: KH: KR is about 2.5∶1∶1.