Inerter-based vibration suppression systems for laterally and base-excited structures

The paper discusses the design and performance of a novel type of passive control system used for suppressing unwanted vibrations in civil engineering structures subjected to both lateral and base excitation. The new control system is inspired by the traditional tuned mass damper (TMD) with the modification that the mass is replaced by an inerter. An inerter has a two-terminal flywheel device capable of generating high apparent mass and its application is now extended from Formula 1 car suspension systems to train suspensions and building base isolation systems. The new control device is named the tuned inerter damper (TID). The tuning of the TID is based on existing tuning guidelines for damped vibration absorbers. We are assessing the performance of the TID in comparison to an equivalent TMD and an equivalent viscous damper, to show the advantages brought by the inerter’s capacity of generating extra apparent mass. The analysis shows that the TID is capable of suppressing the response of higher vibration modes, while the TMD can only control the single mode targeted during the tuning of the device. Moreover, the TID is most efficient when located at the bottom of the structure, which is a potential advantage compared with TMD installation. A multi-degree-of-freedom (DOF) structure is presented as a numerical study to verify our theoretical results. The structure was subjected to base excitation in the form of unit impulse and earthquake load, and to lateral excitation based on wind tunnel tests data. Its performance was similar or superior to that of an equivalent TMD or viscous damper. Therefore, the TID represents a potentially attractive alternative to traditional passive control techniques.