Analytical and Numerical Study of a Passive Self-Tuning Resonator

Abstract: Energy harvesting, from ambient vibrations, can be a very effective method for solving the problem with powering electronics were the need for constant power or regular battery replacements is a trouble or an inconvenience. But, since all energy harvesters, using mechanical vibrations, need to operate in resonance in order to generate maximal electrical output, and ambient vibrations usually do not have a constant vibration frequency, this results in the need for efficient self-tuning systems. This thesis presents an analytical study on the vibrational properties of passive self-tuning systems, based on the clamped-clamped beams and strings carrying a sliding mass. Numerical studies and modal analysis are presented and results are commented and explained. An attempt where made to reproduce the behavior of those systems in the commercial programs ADAMS and ABAQUS, the results and setbacks from those attempts are presented.