Passive Structural Control with the Clutching Inerter Damper with Variable Inertia

The clutching inerter damper (CID) is a passive nonlinear structural control device that converts translational motion into the rotational motion of flywheels, but unlike inerters features one-way clutching mechanisms that prevent energy introduced into the flywheel from being transferred back to the main structure. While the CID can have many positive impacts on the dynamic performance of the structures they are attached to, the instantaneous increase in the structure’s effective mass that occurs with the engagement of the CID can unfavorably impact its performance at high frequencies. This work examines a novel nonlinear mechanism called the clutching inerter damper with variable inertia (CIDVI). The CIDVI incorporates flywheels with passively variable inertia to soften the impact of engagement of the device. In this work, the CIDVI is formulated and numerically investigated. The CIDVI’s behavior and performance is studied by examining the response of a structure with either a CID or CIDVI under a variety of loading conditions. Because of its variable inertance, the CIDVI was able to dissipate its rotational energy more effectively than the CID and reengage with the structure more often than the CID. The performance of the CIDVI was shown to depend on the excitation amplitude; however, in many cases, the CIDVI was able to reduce the high frequency acceleration responses and force transfer otherwise seen with a comparable CID.