Essentially Nonlinear Piezoelectric Attachment for Aeroelastic Flutter Suppression

Various researchers have investigated the behavior of a linear mechanical oscillator weakly coupled to a nonlinear mechanical attachment that has essential stiffness nonlinearity. Under certain conditions, the essentially nonlinear attachment acts as a nonlinear energy sink (NES) and one-way energy transfer from the main structure to the attachment can be achieved. Since an essentially nonlinear attachment does not possess any preferential resonance frequency, they have increased robustness against detuning, enabling frequency-wise wideband performance. In this work, the interactions between an essentially nonlinear piezoelectric attachment and an electromechanically coupled two-degree-of-freedom (2-DOF) aeroelastic typical section are studied. The governing equations of the electromechanically coupled typical section with piezoelectric coupling added to the plunge DOF are presented. An equivalent electrical model of the coupled aeroelastic system is presented and combined to a nonlinear shunt circuit. The performance of the piezoelectric NES to modify the aeroelastic behavior of the typical section is discussed using the short-circuit condition as a reference case. Furthermore, the robustness of the piezoelectric NES against detuning is also investigated by changing some parameters of the typical section.