Comparative Investigation of the Electroelastic Dynamics of Piezoceramics With Interdigitated and Uniform Electrodes

Piezoelectric systems and structures have been used for decades in a variety of applications ranging from vibration control and sensing to morphing and energy harvesting. Conventional piezoelectric ceramics with uniform electrodes typically employ the 31-mode of piezoelectricity in bending, where the 3- and 1-directions are the directions of poling and strain, respectively. In order to employ the more effective 33-mode of piezoelectricity, Interdigitated Electrodes (IDEs) have been used recently in the design of the Macro-Fiber Composite (MFC). In this paper, an investigation into the two-way electroelastic coupling in bimorph cantilevers (in the sense of direct and converse piezoelectric effects) that employ IDEs for 33-mode operation is conducted. To this end, distributed-parameter electroelastic models are developed for the dynamic scenarios that involve two-way coupling, namely piezoelectric power generation and shunt damping as well as the problem of dynamic actuation. Various interdigitated MFC bimorph cantilevers are tested against the model under dynamic actuation, power generation, and shunt damping to identify their modal electromechanical coupling terms. Detailed investigations are conducted by decoupling the system dynamics to keep the direct and converse effects separately pronounced for parameter identification. Additionally, this work sheds light on the literature comparing the electrical power generation performances of 33-mode (interdigitated electrodes) and 31-mode (uniform electrodes) piezoelectric bimorphs of the same volume based on extensive experiments and distributed-parameter electroelastic modeling.