COMPARISON BETWEEN LINEAR AND NON-LINEAR PERFORMANCE OF VIBRATION-BASED PIEZOELECTRIC ENERGY HARVESTERS ROBERTO PALMA ∗ , RAFAEL CASTRO † , ESTHER PUERTAS ∗ AND RAFAEL GALLEGO ∗ ∗ Structural Mechanics and Hydraulic Engineering University of Granada Campus Fuentenueva, 18071 Granada, Spain e-mail: rpalgue@ugr.es † Mechanics University of C´ ordoba Campus Rabanales, 14071 C ´ ordoba, Spain Abstract. Nowadays, the consumption of energy is increasing due to the high quality of life, but society demands more and more the use of clean energy. The production of this type of energy at the macro-scale is solved by wind and solar plants but the micro-energy production is still mostly based on electrochemical batteries that pollute the environment after their useful life. In the context of Structural Health Monitoring (SHM) applied to railways bridges, equip- ment composed of networks with sensors, actuators and wifi devices that require micro-power supplies is needed. One way to avoid the use of electrochemical batteries in these applica- tions could be the use of vibrating harvesters based on smart materials such as piezoelectric, piezomagnetic, etc. These materials work both in linear and non-linear modes. On this ground, this work presents a numerical comparison between both operation modes by using a displacement-based Finite Element (FE) formulation with a) small strains and rotations for the linear response and b) a Saint-Venant-Kirchhoff model for the non-linear regime as a first and good approximation. Both formulations are used to model a piezoelectric harvester for which the prescribed time-dependent displacements are numerically simulated. Finally, the voltages generated by both formulations are compared and several conclusions are highlighted. Key words: Vibrating Harvesters, Piezoelectricity, Non-linear, Finite element method, Experi- mental measurements 1 INTRODUCTION Railway bridges have evolved greatly over the last decades due to two main reasons: increas- ing the public transportation networks and decreasing travel times. The preservation of these 1800 X ECCOMAS Thematic Conference on Smart Structures and Materials SMART 2023 D.A. Saravanos, A. Benjeddou, N. Chrysochoidis and T. Theodosiou (Eds) Available online at www.eccomasproceedia.org Eccomas Proceedia SMART (2023) 1800-1807 © 2023 The Authors. Published by Eccomas Proceedia. Peer-review under responsibility of the organizing committee of SMART 2023. doi: 10.7712/150123.9950.450290