Research Of Seismic Isolation Performance Of Inter-story Isolation Structure Considering Phase Effect

Due to the existence of the isolation layer of inter-story isolation structure,the superstructure and the substructure will produce phase lag phenomenon.The phase lag phenomenon will cause a significant phase difference between the superstructure and the substructure of inter-story isolation structure,and the damping effect of inter-story isolation structure will be amplified under a specific phase difference.Therefore,in order to improve the safety of inter-story isolation structure,this paper explains the influence of the phase difference between the superstructure and the substructure on the damping effect of inter-story isolation structure,The effect of phase difference between superstructure and substructure on the damping effect of inter-story isolated structures is explained,and the factors influencing the change of phase difference are also analyzed,and the effect of phase difference on the damping effect of inter-story isolated structures is further explained by using transfer function as well as energy theory.Finally,the phase is used to supplement the seismic response calculation method of the current stage of inter-story isolated structure,and the seismic response prediction method of interlaminar earthquake structures considering the phase difference is established.Meanwhile,in order to cooperate with the phasebased seismic response prediction method,the phase-based natural ground shaking screening and artificial ground shaking synthesis methods are established to fully consider the influence of phase.In order to achieve the above purpose,this paper carries out the following work on the phase difference between the superstructure and the substructure of inter-story isolation structure(1)The two particles of inter-story isolation structure are established and the motion equation is established.The phase difference formula between the superstructure and the substructure of the story isolation structure is derived.The theoretical analysis of the damping effect of different phase differences is carried out to obtain the optimal phase difference range that can reduce the seismic response of the story isolation structure.And the influence of the superstructure on the substructure is analyzed using the phase difference to provide a theoretical basis for the subsequent study.At the same time,the influence of different parameters and different vibration modes on the change of phase difference is analyzed.Then,the damping ratio of the structure under different mass ratios is optimized by using the principle of minimum base shear and optimal phase difference.In order to further understand the influence of phase difference on the damping effect of inter-story isolation structure,the relationship between phase difference and transfer function is analyzed and the damping mechanism of inter-story isolation structure is expounded.(2)The energy balance equation of inter-story isolation structure is established,and the energy balance formula is derived according to the energy input and output characteristics of interstory isolation structure.Then,the elastic vibration energy,hysteretic energy dissipation of isolation layer and damping energy dissipation of substructure are calculated.Finally,the energy transfer,conversion and consumption of inter-story isolation structure are analyzed,and the influence of phase on the damping effect of inter-story isolation structure is further explained.(3)Since inter-story isolation structure can always reduce the seismic response of the superstructure,but the seismic response of the substructure has a certain uncertainty,and the uncertainty of the seismic response of the substructure is caused by the influence of the superstructure on the substructure,while the phase difference can respond well to this influence,so the formula of the influence of the superstructure on the seismic response of the substructure is deduced by using the phase difference,and the phase difference-based Therefore,the phase difference is used to derive the formula for the influence of the superstructure on the seismic response of the substructure.Finally,the principle of ground shaking screening based on phase is established,and the concept of the most unfavorable input phase of ground shaking is introduced,and the concept of the most unfavorable input phase is used to select the ground shaking.