Tuned inerter damper for adjacent bridges vibration control considering nonlinearities

Abstract

Tuned inerter damper (TID) has been demonstrated as an effective device for vibration control of adjacent structures. However, previous studies normally assumed inerter as a linear device, and applied it to control the vibrations of linear structures. In other words, both the inerter and structural nonlinearities were ignored, which may result in an unreasonable assessment on the seismic responses of adjacent structures. To investigate the influences of nonlinearities on the seismic responses of adjacent bridges, OpenSees software is adopted in the present study due to its capability and convenience in considering structural/material nonlinearity. A new subroutine is developed in OpenSees software to consider TID nonlinearity, and its accuracy is validated by the analytical and experimental results. To examine the TID control effectiveness, finite element (FE) models of adjacent bridges considering structural nonlinearity are established and nonlinear time history analyses are performed to investigate the seismic performances of adjacent bridges with and without TID. The results show that TID is a favourable control device for seismic response control of adjacent bridges, which can mitigate the displacements of bridge decks, drift ratios of bridge piers and delay plastic hinge developments in the bridge piers. Although inerter nonlinearity can potentially enhance TID effectiveness in controlling relative displacement response, structural nonlinearity tends to reduce the TID performances. Furthermore, both the inerter and structural nonlinearities have the potential to intensify pounding forces. It is suggested that nonlinearities should be considered in the seismic response analyses of inerter-enhanced adjacent bridges.