Comparative analysis of nonlinear tuned inerter absorber applied to impact loads

This paper proposes a nonlinear tuned inerter absorber to improve the robustness of tuned mass dampers (TMD) for vibration control and achieve a more lightweight device. The conditions under which the system undergoes targeted energy transfer (TET) are analyzed from the point of view of slow-flow dynamics and nonlinear normal mode for a system subjected to impact loading. An optimal design method for the nonlinear stiffness and damping of the device is proposed, inspired by the existence of an energy threshold and the tuned linear system. Moreover, considering the characteristics of inerter as a class of two-terminal mechanical elements, the performance of the device with and without grounded connections is investigated. It is concluded that the design of the nonlinear stiffness enables the system to enter the TET stage of rapid energy transfer and consumption, and the optimization of the damping of the device further improves the performance of the system after the occurrence of TET. When controlling multi-degree-of-freedom systems, the nonlinear absorber performs better than the corresponding linear absorber when the energy input to a certain mode of the system exceeds the corresponding energy threshold. Furthermore, in relation to this device, the nonlinearity of the ungrounded connection is more easily activated, resulting in a lower energy threshold and more complex dynamic behaviors compared to the grounded approach.