Seismic vibration mitigation of building structures with an Inertial Amplification Mechanism Enhanced Damper (IAM-D)

Combining a mechanical system called the Inertial Amplification Mechanism (IAM) with the spring and the damper, this paper proposes a new passive control system, known as the Inertial Amplification Mechanism Enhanced Damper (IAM-D), for structural seismic vibration mitigation. Using the Fixed-point theory, closed-form expressions for the optimal parameters of the IAM-D are derived. Two optimization criteria are considered: minimizing the maximum displacement and acceleration responses of the primary structure. Compared to the traditional TMD, the superior vibration mitigation performance of the proposed IAM-D is discussed in detail. The influences of the geometrical and physical parameters of the IAM device on the vibration mitigation performance of the proposed IAM-D are investigated. The optimal results for the two optimization criteria are discussed comparatively. Finally, seismic responses of a structure without control, with TMD, and with IAM-D under earthquake ground motions are computed and compared. The results show that the seismic response of the primary structure can be mitigated when the TMD and IAM-D are equipped. Compared to those of the TMD with the same dead mass, the peak values for the displacement and acceleration responses of the primary structure, and the relative displacement response between the absorber and the primary structure for the system with IAM-D, are suppressed by approximately 57%, 16% and 84%, respectively.