Seismic damage performance of a new type of prefabricated frame joints

The construction form of beam column joints affects the mechanical performance of frame structures. A new type of prefabricated frame joints was designed. In order to study the seismic damage performance of the new type of prefabricated frame joints, cyclic load tests were conducted on 8 joint specimens using connection mode and axial compression ratio as the design parameters. The surface strain of the specimens was monitored using VIC-3D technology. The hysteresis curve of the joint and the mechanical properties such as ductility and energy dissipation capacity were analysed. The results indicate that the failure mode of the new prefabricated joints is shear failure, with the main failure locating at the connection between concrete and steel components. The hysteresis curve of prefabricated joints is full, and their energy consumption capacity is strong. The cumulative total energy consumption of prefabricated Z-shaped splicing joints is 1. 75 times that of cast-in-place joints. The ductility coefficient of prefabricated joints is between 2. 02 and 3. 78, and an increase in axial compression ratio will increase the bearing capacity of the joint, while the ductility coefficient will decrease. A modified damage model suitable for prefabricated joints was established, and the calculated damage development curve is consistent with the actual situation. Changes in connection methods can significantly reduce the damage development rate of joints. The smaller the axial compression ratio, the lower the damage development rate. The structural state level of prefabricated frames was quantified. The quantitative results provide a theoretical basis for damage assessment and post earthquake recovery of the structure. © 2024 Chinese Vibration Engineering Society. All rights reserved.