Seismic performance evaluation of ancient Tibetan residential structures and energy dissipation of Mortise-Tenon Joints

Tibet, situated in western China, is renowned for its highland landscape, rich culture, and profound religious heritage. Tibetan-style ancient houses, typical dwellings in this region, reflect the Tibetan people's adaptation to the plateau environment and hold significant cultural, historical, and ecological value. This study used theoretical and finite element analyses to compare the seismic performance of Tibetan houses under various conditions. It evaluated the effects of three types of seismic waves-with and without earth walls-having peak accelerations of 0.4 g and 0.6 g, focusing on interstory displacement angles and top accelerations. Finite element analyses were also conducted on through-tenon and straight-tenon joints to examine stress distributions and hysteresis curves for transverse and smooth grain orientations. Results showed that earth walls significantly enhanced the stiffness and seismic stability of the timber frame. Additionally, through-tenons exhibited fuller hysteresis curves than straight tenons, demonstrating superior energy dissipation.