| Base isolation is easy to cause large deformation of the isolation layer under strong earthquakes,especially under near-fault pulse-like ground motion.In order to reduce the seismic response of the superstructure of the base isolation structure and the displacement of the isolation layer,the piezoelectric friction damper is installed in the isolation layer of the base isolation structure,and the particle swarm optimization method is used to optimize the proposed fuzzy control algorithm.The main research contents of this paper are as follows:(1)The lead rubber bearing is used as the isolation bearing of the base isolation structure,and the Bouc-Wen model is used to simulate the nonlinear hysteretic behavior of the isolation bearing.Different types of ground motions are selected,and the seismic response of the base isolation structure is obtained by using the time history analysis method.By comparing the seismic response of the structure before and after setting the isolation support,the effectiveness of the base isolation under different types of earthquakes is analyzed.(2)The piezoelectric friction damper is installed on the isolation layer of the structure and forms a combined base isolation structure with lead rubber bearing.The mechanical model of the structure is established.Eight ground motions are selected,and the piezoelectric friction damper is semi-active controlled by fuzzy control.The response of the isolated structure is obtained through numerical simulation,and the results are compared with the response of the structure under passive control.The results show that compared with the passive control,although the displacement of the isolation layer increases under the fuzzy control,the acceleration response of the superstructure decreases obviously.(3)The design of fuzzy controller is easily affected by subjective factors.Therefore,particle swarm optimization algorithm is proposed to optimize the membership function and control rules of fuzzy controller.Through numerical simulation,the response of the composite base isolation structure under different earthquakes is obtained.The damping effect is analyzed by using the established evaluation index,and the energy consumption of the damper is analyzed.The results show that the fuzzy control method based on particle swarm optimization can reduce the displacement of the isolation layer without significantly increasing the response of the superstructure,and achieve good damping effect. |
