Inerter-based Building Mass Damper: Optimization and experimental study

The Building Mass Damper is a design concept for vibration control of structures where the upper substructure effectively behaves as a Tuned Mass Damper (TMD) for the lower one. Unfortunately, its tuning usually requires softening or partial isolation of the upper substructure; limiting its applicability for retrofitting. The recently proposed Inerter-based Building Mass Damper (IBMD) is an in-parallel intervention on the upper substructure with an inerter and a damper. Thus, the inerter allows correct Tuning, the upper substructure provides the Mass, and the damper adds the Damping. Therefore, a very large mass-ratio TMD is obtained with marginal additional weight and minimal practical impact. In the present work, experimental tests supported by numerical simulations on a small two-story structure model quantitatively confirm the effectiveness of the IBMD. Besides, an innovative compliant mechanism design is introduced for the implementation of the translation-rotational converter that drives the inerter; which has minimal backlash and friction, still allowing large strokes. The experiments involved a frictional damper, which performed comparable to a linear viscous damper considered in the simulations.