Cluster power flow control of a distributed-parameter planar structure for generating avibration-free zone

Abstract

To generate a vibration-free zone in a designated region of a structure, cluster power flowcontrol is presented. Unlike conventional modal-based vibration control, mainlyused for augmenting structural damping, active wave control can render all thevibration modes inactive; the gain characteristic of a forced vibration responseconverges to the asymptote—to a far greater extent than augmenting structuraldamping; however, progressive waves still remain. Power flow control, advancedactive wave control, allows the generation of a vibration-free zone when properlyconfigured to handle all the governing structural variables. To implement power flowcontrol, cluster control is introduced, which guarantees unconditional stability of afeedback system. To evaluate the vibration-free state, a vibration intensity isintroduced; however, as a result of suppressing the vibration intensity, two extremephenomena arise: suppression or excitation of structural modes. To overcomethis problem, minimization of the dominant structural variables that are thecounterparts of the vibration intensity elements is set up, with the result that avibration-free zone is generated, together with the suppression of the vibrationintensity. A numerical analysis is then conducted, followed by an experiment,demonstrating the capability of the proposed method for generating a vibration-free zone.