Numerical analysis of functionally graded piezoelectric bionic fishtail based on Hermite element-free method

Abstract

Piezoelectric bionic fishtails have good flexibility, response speed, anti-interference ability, and have great application prospects in ocean exploration. However, the inherent drawbacks of the mechanical properties of traditional homogeneous piezoelectric materials significantly affect the propulsion performance and reliability of the piezoelectric bionic fishtails. To fill this gap, this paper develops a functionally graded piezoelectric bionic fishtail (FGPBF) by imitating the tail characteristics of groupers. The geometric structure and working principle of the FGPBF are introduced in detail. Based on the first-order shear deformation theory and Hermite element-free method, an element-free model for the FGPBF is established. The effects of gradient factor, substrate material, substrate thickness and electrical load on the propulsion performance of the FGPBF are addressed. The results show that the current results are in good agreement with the finite element results. The deformation of the FGPBF is negatively correlated with the thickness and stiffness of the substrate and linearly positively correlated with the electrical load. As the gradient factor increases, the deflection of the FGPBF first increases and then decreases. When the gradient factor is 2, the potential is 200 V, the dimensionless aluminum substrate thickness is 1, the propulsion performance of the FGPBF is improved by 28% compared to the homogeneous piezoelectric bionic fishtail.