Novel Tuned Mass Damper with Inerter

Authors: Piotr Brzeski, Przemysław Perlikowski

Projects aimed to analyze the dynamic properties of the tuned mass damper  (TMD) with inerter. The TMDs are widely used to absorb energy from mechanical and structural systems, which translates into increased stability, higher safety and lower operating costs. In the case of structural systems (tall buildings, bridges), TMDs usually have large masses because of the large mass of the damped structure itself. To minimize the mass of TMD, we can add an inerter that acts as an artificial inertance in the system and helps to improve the mitigation of vibrations. However, ineter also give additional profits. Classical tuned mass dampers are tuned to one frequency, hence their efficiency is limited. If one could vary the frequency of the tuned mass damper, the working regime would be much wider. We achieved such a property by adding an inerter with stepless variable inertance to the tuned mass damper. A prototype of the device was built within a project funded by the Ministry of Science and Higher Education [1]. We verified experimentally its usefulness, and we proved that the device mitigated vibrations in a wide range of frequencies. The observed reduction in the amplitude in resonance is 71 times lower than the amplitude of the system without our damper. 

In a second project, funded by the National Centre for Science (NCN), we focused on the TMD with inerer and non-linear damper. In the case of a non-variable inerter it increases the amplitude of the damped structure far from the resonant frequency. This undesirable phenomenon can be eliminated by introducing a non-linear damper, which stiffens the connection between the damped structure and TMD for frequencies much lower or higher than the resonant frequency. During the project realization, we developed a methodology that allows multi-parameter analysis of complex dynamical systems using probabilistic methods. The developed method effectively examines the TMD damping efficiency using different configurations and characteristics of mechanical elements (springs, damper, inerter). Based on the preliminary results, we focused on analyzing the dynamic response of the TMD with a constant inertance of the inerter and a non-linear damper. It was found that the key to the correct and effective operation of the TMD is the simultaneous optimization of the value of the constant inertance and the range of changes of the non-linear damper damping coefficient. The next step was developing experimental rigs to test the characteristics of mechanical elements, thanks to which models of the parts of the main rig were built. Then, the main rig was designed, allowing the experimental confirmation of the project assumptions.

The results obtained in both projects are in line with a very intensively developing branch of mechanics devoted to the mitigation of mechanical vibrations. We have been dealing with the subject of TMD with inerter since 2014. Using an inerter in the TMD structure reduces the TMD mass and increases the effectiveness of damping the main structure vibrations. All our tests were based on realistic parameters, and the design constraints of real-life structures were taken into account.

Experimental rigs designed within the project

Experimental (orange dots) and numerical (black line) conformation of efficiency of the TMD (project [1]). In panel (a) the response of the main system without TMD and in panel (b) with the TMD.

Experimental rigs designed within the project [2]

[1p] P. Brzeski, T. Kapitaniak, P. Perlikowski: “Novel type of tuned mass damper with inerter which enables changes of inertance”, Journal of Sound and Vibration 349, 56-66 (2015).

[2p] P. Brzeski, M. Lazarek, P. Perlikowski: ” Experimental study of the novel tuned mass damper with inerter which enables changes of inertance “, Journal of Sound and Vibration 404, 47-57 (2017).

[3p] M. Lazarek, P. Brzeski, P. Perlikowski: “Design and identification of parameters of tuned mass damper with inerter which enables changes of inertance”, Mechanism and Machine Theory 119, 161-173 (2018)

[4p] K. Mnich, M. Lazarek, P. Brzeski, P. Perlikowski: “Experimental investigation and modeling of nonlinear, adaptive dashpot Meccanica 55, 2599-2608 (2020)

[5p] M. Lazarek, P. Brzeski, P. Perlikowski: “Modeling dynamics of a planetary variator applied in the adaptive TMDVI”, International Journal of Mechanical Sciences 231, 107487 (2022)

[6p] Urządzenie do tłumienia drgań (Vibration’s Damping Device), patent, No. 226532 (Polish patent)