Optimum design of a Tuned-Inerter-Hysteretic-Damper (TIHD) for building structures subject to earthquake base excitations

This paper discusses optimum design approaches for a novel tuned-inerter-hystereticdamper (TIhD) which is a passive vibration suppression device for building structures subject to earthquake base excitations. The TIhD has a linear hysteretic damping element connected in series with an inerter. This device exploits the advantage of linear hysteretic damping which can reduce the structural response amplification at frequencies above resonance, due to the frequency dependent damping. In the present study, the effectiveness of this device in reducing seismic response of building structures is assessed and the optimum tuning of the device parameters is explored. In particular, eight different earthquakes are selected for a case study. The optimum parameters of the TIhD are obtained numerically by using the Self-Adaptive Differential Evolution (SADE) algorithm. The optimisation criterion is the minimum root-mean-square (RMS) value of the top-storey displacement response of the structure. The performance of this tuning configuration is then compared to that of a classically tuned device. The tuning performance is also compared across a range of simulated earthquakes, giving new insight into the challenges of optimising inerter designs that involve hysteretic damping.