11. Linear/Nonlinear Piezoelectric Shell Energy Harvesters

Energy harvesting based on distributed piezoelectric laminated structures has been proposed and extensively investigated for over a decade. The objective of this study is to develop a generic distributed piezoelectric shell energy harvester theory based on a generic linear/nonlinear double-curvature shell, which can be simplified to account for many linear/nonlinear shell and non-shell type distributed energy harvesters. Distributed electromechanical coupling mechanism of the energy harvester was discussed; voltage and power output across the external resistive load of the shell energy harvester were evaluated. Those equations were explicitly expressed in terms of design parameters and modes. Once the intrinsic Lamé parameters and the curvature radii of the selected host structure are specified, one can simplify the piezoelectric energy harvesting equations to account for common shell and non-shell harvester structures. To demonstrate the simplifications, the generic piezoelectric shell energy harvesting mechanism was applied to a cantilever beam, a circular ring and a conical shell in cases studies. Again, the generic piezoelectric energy harvesting formulations derived from a double-curvature shell can be applied to many shell, e.g., ring shells, cylindrical shell, conical shells, paraboloidal shells, etc., and non-shell, e.g., plates, beams, etc., structures using two Lamé parameters and two curvature radii of the specified structures. Besides, these shell and non-shell structures can be either linear or nonlinear with the von Karman geometric nonlinearity. With given boundary conditions and external loading forces, generated voltage and power across the resistive load in the closed-circuit condition can be estimated for the distributed piezoelectric laminated structure.