Reduction of flexural vibration of a fluid-filled pipe with attached vibration absorbers

Abstract

Dynamic vibration absorbers (DVAs) are often used to reduce vibrations in narrow frequency ranges. To reduce the flexural vibrations of a fluid-filled pipe system in a broader frequency band, several DVAs are attached to the pipe periodically to constitute a system akin to a locally resonant phononic crystal. Each DVA is analyzed based on mechanical impedance theory, and Bloch wave theory and the transfer matrix method are used to investigate the wave propagation in such a periodic system. The validity and accuracy of the natural frequencies and dynamic responses obtained are verified by comparing the present numerical results with results from the finite-element method. Also analyzed are the band-gap formation mechanism and how various system parameters influence the band-gap behavior, such as how the lattice and absorber properties influence the location and width of the lowest band gap. Lastly, a mass–spring DVA is designed and attached periodically to find the existence of locally resonant band gaps. The analytical and experimental results show that the mechanical impedance of the DVA is the main factor for the band-gap formation mechanism. When the DVAs are periodically arrayed, it can more effectively control flexural pipe vibration by broadening the bandwidth they attenuate and increase the magnitude of vibration attenuation.