Seismic response analysis of overall friction pendulum bearing (OFPB) isolated structures

The overall friction pendulum bearing (OFPB) is based on the traditional friction pendulum bearing (FPB) proposed as a kind of friction pendulum bearing using the whole large slide. The energy brought by the earthquake is consumed by the overall friction pendulum seismic isolation structure through its large displacement at the bottom. This study aims to analyze the response of the overall friction pendulum seismic isolation structure under earthquake action and to explore its seismic performance. Based on the principles of structural dynamics and the basic theory of finite elements, three models are established in this study using the finite element software ABAQUS: the non-isolated model, the traditional friction pendulum seismic isolation structure model, and the overall friction pendulum seismic isolation structure model. The study takes into account the confinement effects to ensure an accurate simulation of the structural response. Nine seismic waves (seven natural waves and two artificial waves) were selected for seismic time-history analysis. Subsequently, various overall friction pendulum parameters are studied. The results indicate that both traditional friction pendulum seismic isolation structures and overall friction pendulum seismic isolation can effectively reduce the roof acceleration, roof drift, floor acceleration, interstory drift ratio, base shear, and structural damage of the structure. The roof acceleration of the structure can be reduced by 15.78 % to 45.82 % and 45.24 % to 63.61 % by friction pendulum seismic isolation structures and overall friction pendulum seismic isolation structures, respectively. Similarly, the floor acceleration can be reduced by 11.25 % to 60.27 % and 45.24 % to 71.96 %, respectively. The maximum reduction in roof drift is 73.83 % and 74.59 %, the interstory drift ratio is 82.80 % and 83.59 %, and the base shear is 39.12 % and 80.00 %. A certain impact on the control of the structure is exerted by different friction pendulum parameters. The two kinds of isolation structures can play a significant role in earthquake isolation so that the structure can still maintain the elastic design range under the action of rare earthquakes. When facing earthquakes, the overall friction pendulum seismic isolation structure exhibits more significant seismic stability and seismic effect compared with the traditional friction pendulum seismic isolation structure.