Mechanical performance of piezoelectric fiber composites and electroelastic field concentration near the electrode edges

Publication date: 15 August 2017
Source:Materials & Design, Volume 128
Author(s): Xi Yuan, Song Zhu, Xianfang Li, Chao Chen, Kechao Zhou, Dou Zhang
As important smart materials, piezoelectric fiber composites (PFCs) have shown excellent performance in many areas. However, the electric field strength concentration at the edge of the interdigital electrode may lead to crack propagation and eventual actuating failure of PFCs. In this paper, a novel analytical solution on the electroelastic response of PFCs is proposed to characterize the mechanical performance and obtain optimal structure parameters. The problem is converted to a singular integral equation with logarithmic kernel. By solving the resulting equation, the distributions of electric potential, electric displacement, electric field strength, and strain of PFCs fiber are obtained. The finite element method (FEM) is employed to confirm the results. The results demonstrate that the electric displacement and strain of PFCs are dramatically affected by the permittivity properties and piezoelectric constant of materials. The PFCs made by PZT-5H have higher surface electric displacement than PZT-5A and PZT-4. For a ratio of W/L=1/4, both the electric field and strain obtained the minimal value at the electrode edges, which is better for the mechanical performance of PFCs. Moreover, when the thickness of fibers decreases, the actuating performance of PFCs improves and the probability of fracture failure lessens.

Graphical abstract

http://ift.tt/2qLyWdu