Analysis of Electromechanical Response and Fatigue Life of Piezoelectric Cantilever Beam

The electromechanical response and fatigue life of piezoelectric cantilever beam play important roles in restricting the deep application of vibration energy harvesters. Based on the distributed parameter modeling method, the dynamic model of the piezoelectric cantilever was established, and the analytical solution of the electrical output response of the piezoelectric cantilever was solved. With the help of COMSOL simulation software, the finite element model of the piezoelectric cantilever beam was explored, and the accuracy of the theoretical model and the finite element model is verified by the experimental results. We also employed the model to evaluate the influence on the electromechanical response caused by the geometric dimension, the substrate thickness, and the thickness of the ceramic layer of the piezoelectric cantilever beam. Moreover, the influence of various parameters on the fatigue life of piezoelectric cantilever beam was assessed by estimating the S-N curve of piezoelectric material. The results show that the fatigue life of piezoelectric cantilever increases almost exponentially when the width increased from 16 to 24 mm, the base layer and ceramic layer thickened from 0.16~0.24 mm respectively. However, the fatigue life of piezoelectric cantilever decreases significantly when the length of piezoelectric cantilever increases from 48 mm to 56 mm.