| Piezoelectric materials have been found to be effective as both sensors and actuators in many smart structure applications. Although most of the previous studies have been focused on applying piezoelectric actuators on flat structural surfaces, the piezoelectric actuator applications related to complex shaped structures with curved surfaces have been rapidly growing in recent years (examples include aircraft wings, satellite dishes, and space optic mirrors). The main goal of this research is to provide more insights and understanding of the piezoelectric actuation mechanisms on curved structures and provide design guidelines for such systems.; The effectiveness of different types and configurations of surface-bonded piezoelectric actuators on curved beams is examined and evaluated based on rigid curved beam assumption considering the effects of bonding layers. First, an analytical model for curved piezoelectric actuators is developed to investigate the actuation mechanism considering the effects of the interfacial peeling stresses as well as the shear stresses. The average value of the moment distribution calculated from the interfacial stresses is used as a performance index to evaluate the actuation authority, treating the piezoelectric patch as a point moment actuator. Parametric studies on the actuation authorities are performed to examine the effects of parameters: radius, Young's modulus of bonding layers, and thickness of bonding layers, actuators, and host structures. Second, for the analysis of flat actuators, a 3-D finite element method is used to include the effects of interfacial peeling and shear stresses, and similar parametric studies are performed. Finally, experiments are carried out to verify the numerical model. The results show that the effects of interfacial peeling stresses should be considered under certain conditions depending on the system parameters, especially when the thickness of the host structure is relatively thin. It is also observed that the orders of the actuation authorities among a set of three treatment configurations (two with flat actuators and one with a curved actuator) varies significantly with respect to the system parameters. Based on the observations, design guidelines for selecting actuator configurations are suggested. |
