Piezoelectromechanical structures: New trends towards the multimodal passive vibration control

An intelligent control system has the ability to learn about its environment, process the information to reduce uncertainty, plan, generate and execute actions to either control or reduce to a minimum the undesired motion of all or some of its parts. It generally incorporates sensors, actuators, a controller and a power supply unit. Most of the previous work has focused on active control in which electric power is supplied to the actuators that exert actions on the host structure to suppress its vibrations. Alternatively, undesired mechanical energy of a host structure could be converted into electrical energy that can be dissipated through a set of resistor. This does not require an external power unit and is a more economical means of controlling vibrations of a structure, but an effective transduction of mechanical energy into electric energy has to be guaranteed. Such an effective transduction can be achieved imposing to the electric controller to be resonant at all the mechanical resonance frequencies, and to mimic all the mechanical modal shapes, i.e. to be the analog of the host structure. In this paper we synthesize a completely passive electric circuit analog to an Euler beam, aimed for distributed vibration control.