Double tuned mass damper with a grounded inerter for structural vibration control

A Double Tuned Mass Damper (DTMD), which consists of a Tuned Mass Damper (TMD) connected in series with an undamped TMD, has been proven to be more efficient than a traditional TMD in previous studies. To enhance the vibration control performance and robustness of DTMD, an innovative type of DTMD for suppressing structural responses is proposed in this research. This new design includes a DTMD connected to the ground by a linear inerter (abbreviated as DTMDI). After establishing the analytical model of the DTMDI-structure system, the optimal configurations of the DTMDI for different values of inertance are obtained using the Balancing Composite Motion Optimization (BCMO). The effects of the variation in the structural properties as well as the weight and inertance of DTMDI on the performance and robustness of DTMDI are investigated. The present work indicates that an optimal DTMDI is much more effective and robust compared with an optimal DTMD with the same weight. Specifically, the DTMDI configuration with a higher inertance ratio demonstrates increased effectiveness. Moreover, the performance of the DTMDI surpasses that of a TMDI when both have the same mass and inertance, leading to a considerable reduction in the additional weight of the vibration absorber on the primary structure when using the DTMDI instead of the TMDI. While the DTMDI is more robust than both the DTMD and TMD against changes in the structure’s natural frequency, it does not exhibit the same level of robustness as the TMDI when the natural frequency of the structure increases.