Nonlinear modeling of electro-aeroelastic dynamics of composite beams with piezoelectric coupling

Structural and aerodynamic non-linearities can lead to persistent oscillations in aeroelastic systems, which allows the conversion of mechanical energy into electric power. Flexible beams represent an example of structures that can be used as energy harvesters. This work aims to model and analyze the non-linearities induced by the flow-structure interaction of an energy harvester consisting of a laminated beam integrated with a piezoelectric sensor. The cantilevered beam and the piezoelectric lamina are modeled using a nonlinear finite element approach, while unsteady aerodynamic effects are described by a state-space model that allows for arbitrary nonlinear lift characteristics. Wind tunnel tests for a fluttering beam in a broad range of flow speeds and preset angles of incidence were used to validate the electro-aeroelastic model. The matching of experimental and computational results reveals the importance of appropriately modeling structural and aerodynamic non-linearities for reproducing the physical electro-aeroelastic behavior of the system. These findings are of practical and theoretical relevance, and are further supported by the model's complete inability to reproduce experimental results when either of the non-linearities are “switched off”.