Strategy of damping vibration of structures with piezoelectric elements and external electrical circuits and their experimental illustration

This paper presents basic concepts of smart-materials and strategies of vibration damping structures with piezoelectric elements and external circuits, based on the well-known works. Different variants of external passive electrical circuits consisting of resistors, inductance and capacitance, and the main circuit of active electric circuits with feedback and feed forward adaptive filtering are considered. The authors presented the results of experimental studies on damping vibrations of cantilever steel beam with different types of external passive electrical circuits and the locations of piezoelectric elements. Research results lead to the following conclusions: the use of resonant circuits for the damping of vibrations of the structure is more effective than the resistive circuits; vibration damping increases when piezoelectric elements are placed in the zones with the largest gradient forming; parallel connection to an external electrical circuit of additional piezoelectric elements allows achieving a greater degree of vibration damping and decrease of values related to optimal inductance and resistance; there are modes of vibration of structures, in which there are no sufficient in size electric potential at the surface of the piezoelectric elements, to be able to use the piezoelectric damping of the oscillation mode; optimal parameters of a shunt circuit for the corresponding vibration modes do not depend on the amplitude of the oscillations determined by levels of external influence. The paper presents the results of the experiment on damping vibrations at impact loading through the use of the active external electric circuit in case of feedback control.