Enhanced seismic base isolation using inertial amplifiers

Abstract

Harnessing the concept of inertial amplification, an inertial amplifier coupled base isolator (IABI) is proposed in this paper. The seismic performance, in terms of story drift, base shear reduction, of this proposed inertial amplifier coupled base isolator has been compared with that of the classical base isolator (CBI) and inerter-based isolation system (Inerter-BI). A thorough analytical study, implementing rationals of random vibration for harmonic and Gaussian white noise is conducted to identify the performance of the inertial amplifier coupled base isolator (IABI) in the frequency domain. Further, a numerical study is conducted to determine the story drift, base shear response in time-domain for the inertial amplifier based base-isolated structure and classical base-isolated structure for twenty-two real earthquake ground motions. The results elucidate the histogram of base shear and story drift reduction percentage shifts towards higher values for inertial amplifier coupled isolator compared to CBI and Inerter-BI. From both analytical and numerical study, it is observed that the seismic performance and response reduction capacity of proposed IABI is significantly 89.38% and 72% superior to the classical base isolator and inerter-based isolation system, respectively. This finding evidenced towards the supremacy of the inertial amplifier base isolator over the classical base isolator and inerter coupled base isolator in terms of seismic vibration control.