Numerical predictions for the effective electrical properties of flexoelectric composites with a single inclusion

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2021-09, Vol.127 (9), Article 686
• Main Authors: Zheng, Yicong, Chu, Liangliang, Dui, Guansuo, Zhu, Xiang
• Format: Article
• Language: English
• Subjects: Applied physics; Characterization and Evaluation of Materials; Condensed Matter Physics; Electric fields; Electrical properties; Finite element method; Machines; Manufacturing; Materials science; Mathematical analysis; Micromechanics; Nanotechnology; Numerical prediction; Optical and Electronic Materials; Particulate composites; Physics; Physics and Astronomy; Processes; Shape effects; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-021-04832-y

The direct flexoelectricity in dielectrics, as an electromechanical mechanism coupling electric field and strain gradient, exhibits strong size dependence and structures associated. In the present paper, the effective electrical properties of particulate flexoelectric composites are predicted by the flexoelectric theory. Depending on the theory of micromechanics homogenization, numerical finite element simulations have been finished for representative volume elements (RVE) of the isotropic matrix filled with a single flexoelectric inclusion, by using mixed variational principle and finite element method (FEM). The electric fields inside the RVE of different inclusion shapes and volume fractions are studied. The influence of length scale on the electrical properties of the composites is discussed. Effective electrical properties of the composites are estimated based on obtained numerical results. It shows that the shape of the inclusion has a great influence on the effective electrical properties of composites with a nano-scale inclusion. The regular octagonal inclusion can provide high electrical performance and effective electrical properties are even twice as large as the spherical inclusion. At the same time, the selection of the length scale will affect the effective electrical properties. Our results, suggest that the shape effect of the inclusion on electrical properties of nano-scale dielectric composites should be emphasized.