The reduction of structural vibrations on the example of two pedestrian bridges (in Poznań and Wrocław) with using of tuned mass dampers (TMD) has been presented in the paper. The results of theoretical and experimental studies of pedestrian bridge vibrations has been described and discussed. Basing on the results of calculations and measurements, tuned mass dampers (TMD) has been designed and mounted in the structure of the bridges. The measurements after the assembly of TMD show a high efficiency of vibration damping.

The paper concerns the optimization of a tuned mass damper with inerter (TMDI) based on two strategies, i.e., the minimum amplitude in the resonance peak and minimum area under the frequency response curve. The optimization is based on real, accessible parameters. Both optimization procedures are presented in two steps. In the first one, two parameters of the TMDI are tuned (inertance and damping coefficient), while in the second one, three parameters (mass, inertance, and damping coefficient). We show that both strategies give the optimum sets of parameters and allow the reduction of the amplitude of the damped system.

The application of tuned liquid column dampers (TLCD) for suppressing excessive lateral pedestrian-induced vibrations of footbridges is investigated experimentally and numerically. In order to study the effectiveness of TLCD, a novel three-degree-of-freedom (DOF) bridge model is constructed in the laboratory of the TU-Institute. A single TLCD is attached to the bridge model to counteract the bridge's fundamental vibration mode. Modal tuning of the TLCD is performed using an analogy to tuned mass damper (TMD). A new excitation device has been developed for simulating the time-periodic contact forces due to walking pedestrians. All vibration tests performed indicate a large reduction of the maximum lateral vibration response amplitude. In order to verify the experimental results, numerical simulations of the laboratory model are performed, which show a good agreement. The application ofTLCD at least doubles the effective modal damping coefficient when compared to the original bridge model.