Mechanical Model and Seismic Response Analysis of a Track Type Combined Isolation Device

Abstract

In view of the weak isolation and shock absorption effect of ordinary isolation bearings at present, a new track damping negative-stiffness device was designed based on the principle of negative stiffness. The principle of negative stiffness was applied to base isolation, and a new isolation system was proposed in which the track-type NSD device and the common isolation layer were connected in parallel. The track-type NSD had the characteristics of clear force transmission, simple structure, and self-resetting ability. The theoretical model of orbital NSD was established, and its hysteretic performance was simulated. The seismic response of a six-story reinforced-concrete-frame isolation structure system with a new track-type-damping negative-stiffness device was analyzed. The seismic responses of the traditional lead rubber bearing isolation model (LRB), the new track-type negative stiffness and lead rubber bearing combined isolation model (NSD), and the new track-type-damping negative stiffness and lead rubber bearing combined isolation model (DNSD) were compared. The results show that, in the same case, compared with the LRB model and NSD model, the DNSD model will further reduce the superstructure acceleration response and displacement response of the isolation system, and the greater the peak value of the input seismic wave, the more obvious the isolation effect of the structural system. The new track damping negative-stiffness device enhances the energy dissipation capacity of the structural system and plays a role in controlling the displacement of the isolation layer. The displacement response of the isolation layer and the ground motion response of the superstructure are reduced at the same time, and the isolation efficiency is improved.