Numerical study of resilient steel frame with SIFS under bi-directional earthquake

Aiming at the problem of the ' expansion effect ' of the resilient steel frame (RSF)under earthquakes causing serious damage to the floor, a resilient steel frame with a seismic isolated floor slab (RSF-SIFS) is proposed. The shaking table test has verified that RSF-SIFS has strong post-earthquake resilience. However, it does not compare the resilient steel frame with the rigid floor (RSF-RF) in terms of damping performance, horizontal force transmission, and post-earthquake resilience function. The connection stiffness between the slab and the main structure is analyzed theoretically. Then, the numerical model is established, and the analysis results are compared with the shaking table test results. The first-order frequency deviation is 0.72 %, and the second-order frequency deviation is 1.49 %, which is in good agreement. The dynamic response of RSF-SIFS under bidirectional earthquake is analyzed by numerical simulation and compared with RSF-RF. The results show that the maximum stress of the floor is reduced by more than 74.85 %, effectively avoiding the damage of the floor. The seismic isolated floor slab (SIFS) can effectively reduce the seismic response of the structure, and the maximum inter-story drift angle is reduced by more than 46 %. The shear force deviation of the steel columns of the two structures is not more than 10 %, indicating that SIFS can effectively transfer the horizontal shear force. The residual drift angle of RSF-SIFS is smaller than that of RSF-RF under bidirectional earthquake of each magnitude, and the post-earthquake resilience is better.