Vacuum plant for structured fabric TVA

This paper presents the design and the implementation of a new tuneable vibration absorber made by a beamlike in-vacuo composite structure held by a post in the middle, whose fundamental flexural natural frequency can be tuned by modulating the vacuum pressure. More specifically, the structure is made a core chain mail fabric encased in a deflated plastic skin. The vacuum is provided through the post by a control plant formed by a pump, two electromechanical valves and a pressure sensor, which are connected to a digital controller. The paper presents in detail the design, construction and online implementation of the structured fabric absorber and vacuum controller. Also, it provides a set of preliminary tests made to identify the vibration response of the absorbers with respect to measurements of the base impedance and vibration transmissibility. Finally, it shows initial results on the control performance produced by the absorber when it is mounted on a thin plate model structure to control the resonant response of target flexural modes.