High accuracy comsol simulation method of bimorph cantilever for piezoelectric vibration energy harvesting

Piezoelectric bimorph cantilever is a typical structure for vibration energy harvesting. This paper studies the method to improve the accuracy of FEA (finite element analysis) simulation for piezoelectric bimorph cantilever. The COSMOL simulation methods based on 1 D (dimension) model of Euler Bernoulli beam, as well as 2 D and 3 D models of solid mechanics are proposed respectively. Compared with the theory and experiment results given by Erturk A, the influences of 1 D and 3 D piezoelectric material parameters on simulation accuracy in FEA modeling is discussed. The simulation error can be reduced to less than 1.2% by using 1D piezoelectric material parameters in COMSOL simulation, while the maximum simulation error can be up to 28% by using 3D piezoelectric material parameters. Comparing serial and parallel configurations of piezoelectric bimorph cantilever, the output electrical powers, varying with the excitation frequency and load resistance, are also discussed in COMSOL simulation. Performance comparation of three kinds of piezoelectric bimorph cantilevers with tip mass shows that the modelling and simulation in finite element methods by COMSOL are simple and convenient, and are suitable for the electromechanical coupling analysis and optimization of complex topological structures.