Method and Experimental Study of Oscillator Frequency Optimization of Distributed Tuned Mass Dampers for Broadband Multimodal Vibration Mitigation of Reinforced Concrete Wall

Distributed tuned mass dampers (dTMD) can effectively mitigate the broadband vibration of a structure. However, when the vibration frequency in question reaches several hundred hertz, traditional optimization methods represented by fixed point theory are difficult to apply due to dense modal density, complex boundary conditions, and vibration inputs. This paper proposes the minimax method based on modal damping to optimize the oscillator's frequency. Two typical wall panel specimens are tested to evaluate the proposed method. The mode shape of the uncontrolled wall and the vibration mitigation effect of the stacked sandwich-damped TMD under single-point bidirectional excitation is tested. The correlation between the modal damping and the vibration mitigation effect is evaluated. The results show that the RC wall panel has a dense mode when the frequency of interest reaches 300 Hz and above; the distributed stacked sandwich-damped TMDs can effectively mitigate the vibration of the RC wall panel in the frequency range of 200 similar to 450 Hz; and that the idea of optimizing the frequency of dTMD based on modal damping is feasible.