Experimental Study on Wooden Pin Reinforcement of the Typical Mortise-Tenon Joints of Ancient Timber Frames

The ancient timber frames is the precious architectural heritage of China. The seismic performance of mortise tenon joints (MTJ) directly affects the seismic performance of the ancient timber frames. This study presents a method that utilizes wooden pins to reinforce MTJs, enhancing the seismic performance of timber frame structures. The quasi-static test and finite element model were carried out to study the mechanical properties of the MTJ reinforced by the wood pins. From the failure state of the MTJs, it is found that the main deformation is the slip deformation between mortise and tenon. The mutual friction between the mortise and the tenon has a certain energy dissipation and shock absorption effect. The deformation state, stress distribution, stiffness degradation curve, etc. of the MTJ were obtained by finite element model of the MTJ. Additionally, the study confirms that reinforced MTJ can help restrict displacement changes within the wooden frame. The results show the bearing capacity of MJT reinforced with wooden pins is approximately 11.3% higher compared to that of MTJ without reinforcement. The reinforcement of wood pins effectively controls the horizontal displacement of the wooden frame, which is reduced by about 50%-62% compared with the unreinforced wooden frame. The locating the wooden pin-reinforced MTJs in the outer columns and middle layer columns reduces structural displacement, which is 31.53% in X derection, 5% in Y derection, 25.86% in Z derection.