Managing property distribution errors in arrays of coupled resonators

Arrays of small attachments can be designed to draw mechanical energy from a primary structure in a manner far in excess of their proportional size. Earlier work has shown that slight variations or errors in the property distributions of arrays of coupled resonators can have a dramatic effect on the response of primary structure to an external force. This work investigates the use of an electro-mechanical approach to making small adjustments in the stiffness of the individual elements of the array to alter the response of the primary. The electro-mechanical coupling is achieved by way of laminated thin piezoactuators mounted on a fraction of the subordinate elements. The piezoactuators are electrically coupled to a switching network that changes the effective stiffness of the subordinate elements. This ability to adjust the stiffness distribution facilitates real time control of the rate at which the energy is transferred into the coupled array. This apparent damping can then be adjusted to draw or reject energy from specific frequency bands. The presentation will describe the underling theory, present numerical results, and some preliminary experimental results.