| In this research project, novel structural control methods employing piezoceramic materials are explored. A great deal of research has focused on passive vibration control using shunted piezoceramic actuators as a simple and low-power means of adding damping to vibrating structures. This research investigates novel semi-active vibration control techniques in which the piezoceramic shunts will be switched in real-time. By switching between open-circuit and either a ground shunt circuit or a resistor/inductor shunt circuit in real-time, the electrical charge generated by the piezoceramic element can be used effectively to dissipate structural energy. This research project explores the performance potential of two single mode switched shunt approaches, the state switching and the synchronized switching techniques. It answers key questions about these switching methods, develops a complete understanding of their capabilities and limits, and puts them into context with other “conventional” passive and active structural control approaches. It is shown that the synchronized switching technique will, in general, perform better than the state switching technique, will perform the same as, if not better than, the traditional resonant shunt technique, and it can be significantly less sensitive to tuning or to changes in structural parameters than the traditional resonant shunt technique. Also, this research project develops and implements a new piezoceramic switching shunt circuit, semi-active multi-modal energy rate vibration control technique. This technique is shown to control up to three low frequency modes of both analytical and experimental test structures while using a switching resistor/inductor shunt. The new multi-modal technique shows great promise as a simple and low power means to add damping to multiple modes of vibrating structures. |
