Resilient joints with SMA bar-shear friction damper (SSFD) device in steel modern Chinese traditional-style buildings: Seismic performance evaluation and optimized design

To inherit and protect ancient Chinese architectural culture, modern building materials and techniques have been combined in the modern Chinese traditional-style building (MCTB) with similar exterior forms to ancient Chinese timber architecture. However, the typical joint in MCTB exhibits weak energy dissipation capacity and significant residual deformation under seismic actions, resulting in a problematic post-earthquake repair behavior. A semi-rigid friction-damped joint with resilient function has been proposed to improve the seismic performance and recoverability of MCTBs. Low-cyclic loading was conducted on four specimens of full scale. The results indicated that the yielding failure of four specimens primarily occurred in the vulnerable regions designed with replaceable angles. Compared with semi-rigid joints, the yield displacement, overall strength, initial stiffness, and cumulative energy dissipation of the specimen with the shape memory alloy (SMA) bar-shear friction damper device was significantly increased, and the residual deformation was significantly reduced, indicating that the device has a significant enhancement effect on the seismic and repairable performance of the structure. Based on the experimental results, a three-dimensional model was established using ABAQUS finite element software to optimize the design of joints and determine the optimal structural system that meets the requirements of MCTB.