Multi-objective Optimization of Piezoelectric Energy Harvester Combined with Euler Buckled Beams Type Nonlinear Energy Sink

In recent decades, considerable attention has been given to multi-functional energy harvesting devices for achieving vibration mitigation and energy harvesting at the same time. In this study, a novel piezoelectric Euler-buckled beams type nonlinear energy sink (PEBNES) with functions of vibration mitigation and energy harvesting has been proposed. The proposed PEBNES is integrated with an Euler-buckled-beam-type nonlinear energy sink and a piezoelectric energy harvester which consists of piezoelectric patches and a harvesting circuit. Based on the electromechanical coupling mechanism, the coupling kinetic equations of PEBNES attached to primary vibration system under harmonic excitation are established. In order to simultaneously improve vibration attenuation and energy harvesting efficiency of PEBNES, a multi-objective optimization by means of non-dominated sorting genetic algorithm-II (NSGA-II) is used to optimize the design parameters of PEBNES for minimization the displacement amplitude of the primary vibration system and maximization harvesting voltage. And the optimization results are evaluated in terms of the harvesting power and displacement amplitude of the primary vibration system. It is concluded that PEBNES effectively reduces vibration of the primary vibration system and has a satisfactory energy harvesting capability. Moreover, the displacement response of the primary vibration system can be further reduced by 63.82% while harvesting voltage is increased by 418.6% after optimization.