Piezoelectric materials exhibit electromechanical coupling properties and have been gained importance over the last few decades due to their broad range of applications. Vibration-based energy harvesting systems have been proposed using the direct piezoelectric effect by converting mechanical into electrical energy. Although the great relevance of these systems, performance enhancement strategies are essential to improve the applicability of these system and have been studied substantially. This work addresses a numerical investigation of the influence of cubic polynomial nonlinearities in energy harvesting systems considering a bistable structure subjected to harmonic excitation. A deep parametric analysis is carried out employing nonlinear dynamics tools. Results show complex dynamical behaviors associated with the trigger of inter-well motion. Electrical power output and efficiency are monitored in order to evaluate the configurations associated with best system performances.
The nonlinear dynamics of a runner are reported here. Image processing software is used obtain experimental data of the 2-D leg motion of the athlete. The available power that the athlete creates from this motion is calculated for multiple speeds. The multi-frequency motion is then filtered, recreated numerically, and compared to the experimental data. This entire process is repeated for multiple athletes of different backgrounds and skill levels. The frequencies at which large amounts of power are available are compared for each athlete in order to find any possible commonality.
Dynamics of composite nonlinear systems and materials for engineering applications and energy harvesting – The role of nonlinear dynamics and complexity in new developments