A MODEL FOR EVALUATING THE MODAL FREQUENCIES AND ENVIRONMENTAL VIBRATION ENERGY HARVESTING CAPACITY OF RECTANGULAR PIEZOELECTRIC BEAMS.

Environmental vibration energy harvesting has received widespread attention recently, but existing research mainly focuses on cantilever beams. The fixing method of the cantilever beams limits its application range. A theoretical model and experimental results of a rectangular piezoelectric beam's modal frequencies and environmental vibration energy harvesting capacity are presented in this study. Accurate evaluation of piezoelectric beams' modal frequencies and energy harvesting capacity is extremely important to monitor and harvest energy from environmental vibrations. This paper establishes a model for the modal frequencies and response of a rectangular piezoelectric beam based on the Euler-Bernoulli beam theory and piezoelectric constitutive equation. In this paper, a fixed-size rectangular piezoelectric beam was selected for verification. The theoretical model was calculated using the modal superposition method. Then, the modal frequencies of piezoelectric beams were simulated using COMSOL, which is a multiphysics simulation software, and compared with theoretical values. Next, the modal frequencies of the piezoelectric beams and the vibration response of the theoretical results were verified through multiple sets of experiments. The experimental results show that the theoretical evaluation error of the modal frequencies of the piezoelectric beams is 1.23%, and the calculation average errors of the output voltage and power of the rectangular piezoelectric beams are 2.7% and 12.3%. The theoretical model effectively predicted the modal frequencies, output voltage, and power of the rectangular piezoelectric beams, demonstrating its potential for monitoring and harvesting environmental vibration energy. [ABSTRACT FROM AUTHOR]