Performance of a Novel Inerter-Based Isolation System for Medium-Rise Buildings Under Seismic and Wind Excitations

Base isolation is a useful technique to mitigate superstructural vibrations based on the principle of shifting structural natural frequencies lower than the dominant frequency range of seismic excitations. However, excessive displacement may be concentrated at the flexible substructure, causing the loss of its building functions. Besides, the conventional isolation systems make the building structures, especially the medium- and high-rise ones, be vulnerable to wind excitations. This paper presents a novel inerter-based isolation system and investigate its seismic isolation and wind resistance performances through a 12-story RC building model. First, the isolation principle of the inerter-based isolation system is investigated based on an equivalent 2-DOF model. Also, the optimization scheme for the inerter-based isolation system is proposed. Then, the spectral representation methods (SRM) for 1d-1v and 1d-Nv stochastic processes are utilized to generate the time history samples of seismic and wind excitations, respectively. Last, the performance of the inerter-based isolation system is evaluated in time domain. The results show that the inerter-based isolation system can achieve the comparable seismic isolation effect for the superstructure without reducing the physical stiffness of the substructure so that there are not amplified displacement. Meanwhile, the inerter-based isolation system exhibits a satisfying performance under wind excitations, which means that it is a preferable isolation technique for building structures located in both seismic and typhoon fields.