Research on tunable cantilever beam distributed vibration absorbers

Abstract

Distributed vibration mitigation by distributed absorbers suppresses line-spectrum vibrations within a defined bandwidth through the installation of absorbers with different tuned frequencies along the structure. Based on a cantilever-beam–discrete-mass system, this work proposes a simple cantilever-beam distributed absorber design. It investigates how the cantilever’s geometric parameters, the magnitude of the lumped mass, and its location influence the system’s natural frequencies to achieve tuning of the absorber frequencies; on this basis, a pair of immersed porous disks is introduced. By adjusting the inter-disk angle, the porosity changes are induced, thereby modulating the contact area between the disks and the liquid inside the housing to realize tunable damping of the absorber. In practical applications, the number of distributed absorbers and the corresponding optimal design parameters are first determined; subsequently, several cantilever-beam absorbers are integrated and mounted on a common fixed boundary, and the parameters of each independent cantilever-beam absorber are adjusted to their optimum values.