Plug-in seismic isolation joints in modular steel structures: Experimental and numerical evaluation

Abstract

This paper introduces an insertable seismic-isolation and energy-dissipation connection joint tailored for modular steel structure buildings. To explore the seismic isolation and energy-dissipation performance of this innovative joint, cyclic loading tests were conducted on a two-story steel frame model equipped with the proposed joints. This study systematically analyzed the deformation patterns and seismic behaviors of the joints and established a mechanical model through theoretical analysis. The test results show that the proposed joints exhibit excellent energy dissipation and damping capabilities, which enables them to enhance the seismic resistance of modular steel structures effectively. In addition, the ETABS software was used to conduct modal decomposition response spectrum analysis and time-history analysis on a modular building. The simulation results show that introducing seismic isolation joints increases the average natural period of the structure under seismic action by 244%. Further analysis reveals that the isolation structure has a more significant damping effect on the lower floors compared to the non-isolation structure, and the damping effect under rare earthquakes is better than that under design earthquakes. Although the calculation results of the time-history analysis method are more conservative than those of the modal decomposition response spectrum method, both methods indicate that the new seismic isolation joints have a significant damping effect and can effectively improve the seismic performance of the structure under seismic action.