The retuner: A low energy and slow timescale control device for the re-tuning of a suboptimal tuned mass damper

Tuned mass dampers (TMDs) have been widely studied and used for mitigating the structural vibrations induced by environmental loads such as wind, earthquakes, and traffic. Nevertheless, the effectiveness of TMDs can be compromised when confronted with uncertainties coming from either structural parameters or environmental loads. Such deviations from the optimal tuning configuration can substantially impact their mitigation efficacy. The retuner, a new concept in the field of structural dynamics, is an additional mass–spring system that can be incorporated in series with the TMD to reduce its sensitivity to mistuning. Remarkably, in the presence of mistuning, the judicious adjustment of retuner parameters enables an interaction with TMD parameters, thereby restoring the TMD’s original performance. Exploiting an eigenvalue- based approach, the design of the retuner system is made simple and guided by analytical criteria, offering ease of implementation and broad applicability. Being a simple addition to a well-known system, the retuner is an efficient and low-cost alternative solution for structural vibration control.