How the decayed straight mortise-tenon joints influence the seismic performance of ancient timber building? Evidence from experiment scenarios of the benchmark wood frames

This paper focuses on the effect of the decay damage of the ancient timber building (ATB) with the one-way straight mortise-tenon (OWSMT) joints on the seismic performance of the wood frame (WF). The artificial damage simulation method was used to consider the varying degrees of damage to OWSMT joints considering the damage depth and surface damage of the mortise. Three damaged WFs with three different joints damage and a non-damaged WF were made according to the Song Dynasty's Construction Formula. The scale of reduction was 1:3.52. Moreover, they have carried out low-cycle loading tests on the four WFs, compared and analyzed the strain variation characteristics at the edge of the OWSMT joints. Besides, the study discussed the hysteretic features, stiffness degradation, and energy dissipation capacity of the WF. The results show that the damage depth of mortise has a more significant impact on the seismic performance of the WF.