A Simplified Approach to Geometric Non-Linearity in Clamped–Clamped Plates for Energy-Harvesting Applications

Energy-harvesting devices utilizing the Vortex-Induced Vibration (VIV) phenomenon are gaining significant research attention due to their potential to generate energy from small water flows, where conventional hydroelectric plants are impractical. Developing effective design methods for these systems is therefore essential. This study focuses on a critical configuration of such devices where energy extraction is achieved by harnessing the oscillatory deformation of two clamped–clamped plates, positioned downstream of the bluff body and subject to the effect of the vortex street. To simplify the preliminary design process, a semi-analytical approach, based on energetic considerations, is proposed to model the non-linear oscillations of the plates, eliminating the need for numerical simulations. The accuracy of this method is assessed through comparative analyses with finite element method (FEM) analyses, under both static and dynamic deformation conditions. The results validate the effectiveness of the proposed approach, offering insights into the effect of the adopted simplifications. In this framework, potential improvements to enhance the method’s reliability are identified. Thus, the work provides a practical model to address the preliminary design of these devices and suggests pathways for its further enhancement.