Vibration Control of Footbridges Based on Local Resonance Band Gaps

Abstract

As footbridges are lightweight and slender structures, they are highly sensitive to human-induced excitation, and control measures are required to suppress undesirable structural vibrations. As wave propagation is improbable within a band gap, this study introduces a band gap in a footbridge and develops a new technique as an alternative to suppress the human-induced vibration response. Inerter-based dynamic vibration absorbers (IDVAs) are arranged periodically in the footbridge, which can convert the conventional box girder into a specially designed periodic metamaterial beam with a local resonance band gap. Following the spectral element method, the band gap structure of the metamaterial beam with IDVAs is proposed and validated by test results and numerical experiments. The band gap structure can be simultaneously tuned by the parameters of the IDVAs, including spring stiffness, inertance, and attached mass. A computer-based program was presented to determine the reasonable design parameters of IDVAs. Finally, a new vibration attenuation method for footbridges is proposed based on the theory of metamaterials and validated by numerical experiments. The results show that the proposed method exhibits good performance in vibration attenuation.