STUDY ON PERFORMANCE IMPROVEMENT OF BASE-ISOLATED STRUCTURES USING BAND-LIMITED RATE-INDEPENDENT LINEAR DAMPING

Rate-independent linear damping (RILD) that is also known as complex-valued damping or linear hysteretic damping is effective for controlling isolator displacement when it is incorporated into a seismically isolated structure. This study shows a band-limited RILD model with a constant damping ratio in a frequency-band of interest can maintain or even surpass the seismic isolation performance of RILD when the stiffness of the superstructure is relatively high. We show a causal model mimicking the damping characteristics of the band-limited RILD and identify that the reduced seismic isolation performance of the causal model compared to RILD is mainly caused by storage stiffness.