Analysis of the Influence of Mortise-tenon Joint Damage on Seismic Performance of Ancient Timber Structure

This research investigated the influence of mortise-tenon joint before and after damage on seismic performance of ancient lifted-beam timber structure. Dynamic responses of an ancient timber structure under various earthquake intensities were analyzed by ANSYS to extract the M-theta. hysteresis loops of mortise-tenon joints before and after damage. The area of the largest hysteresis loop was taken as quantitative indicator to measure energy dissipation of mortise-tenon joints. The results shows that if some mortise-tenon joints were damaged, they dissipated much less earthquake energy decreasing by 31.8%-38.5%, and top displacement of structures increased by 1.79%-5.96% correspondingly. Moreover, the displacement under 8-degree-fortification, 7-degree-rare earthquake intensity increased most obviously. Therefore, energy dissipation of mortise-tenon joint is a main indicator to the assessment of seismic performance of a damaged ancient timber structure.