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Electric Dipole Model and Computer Simulation of the Fracture Behavior of a Conductive Crack in a Dielectric Material

Published online by Cambridge University Press:  01 February 2011

Tianhong Wang
Affiliation:
Department of Mechanical Engineering, The University of Akron Akron, OH 44325, U.S.A.
Xiaosheng Gao
Affiliation:
Department of Mechanical Engineering, The University of Akron Akron, OH 44325, U.S.A.
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Abstract

Fracture tests on poled and depoled lead zirconate titanate (PZT) ceramics indicate that purely electric fields are able to propagate the conductive cracks (notches) and fracture the samples. To understand the fracture behavior of conducting cracks in ferroelectric ceramics, an electric dipole model is proposed, in which a discrete electric dipole is used to represent the local spontaneous polarization and the force couples are used to represent the local strains. The electric dipole model provides basic solutions for microstructural modeling. The microstructural modeling is based on a domain switching mechanism. The domain structure is simulated with a grid of points where polarizations and strains vary with the applied loads. As a first step study, the microstructural modeling is conducted for a dielectric material with a conductive crack. The simulation result explains why the electric fracture toughness is much higher than the mechanical fracture toughness.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

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