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Acta MechanicaActa Mechanica 185, 201214 (2006)DOI 10.1007/s00707-006-0344-5H. G. Beom, Incheon, and K. J. Kang, Kwangju, KoreaReceived September 15, 2005; revised February 25, 2006
Published online: July 6, 2006 Springer-Verlag 2006Summary. Crack kinking induced by domain switching in a ferroelectric material under purely electricloading is investigated. Boundaries of domain switching zones for the asymptotic problem of a semiinnite crack under the small scale conditions are determined based on the nonlinear electric theory.Stress intensity factors induced by the domain switching are numerically evaluated using the solution ofthe switching zone. Numerical results of the kink angle are obtained as a function of the ratio of thecoercive electric eld to the yield electric eld for various polarization angles. Crack kinking in ferroelectric materials subjected to a cyclic electric eld is also examined. The crack in the fully poledmaterials branches with dierent directions at application of the positive and negative electric elds,respectively. The electric fatigue crack is shown to have a forked crack pattern in the fully poledmaterials.Ferroelectric ceramics have attained much attention recently for applications in electromechanical sensors, actuators, and nonvolatile random access memories. The reliability of ferroelectric ceramics under combined electrical and mechanical loadings is a challenging issue. Itis of great importance to understand the fracture behavior since fracture due to crack growth isthe serious limitation of the ferroelectric materials. Extensive studies on the subject of crackshave been carried out by many researchers [1]. Theoretical progress has been made in investigating the eect of electric elds on the fracture behavior of nonlinear ferroelectric ceramics.Gao et al. [2] studied the inuence of the electrical nonlinearity on the fracture of a piezoelectricmaterial by using the strip saturation model. Recently, Beom and Atluri [3] proposed a nonlinear domain switching model. Their model gives a theoretical explanation for the experimental observation on various fracture behaviors of ferroelectric materials under combinedelectric and mechanical loading. Subsequently, Beom and Jeong [4] investigated the eect ofdomain switching on crack growth in a ferroelectric material with perfect electric displacementsaturation under electric loading.When a crack in an elastic material subjected to mixed mode loading grows, the direction ofcrack propagation makes an angle with the existing crack line. The problem of kinked cracks inelastic materials has thus been extensively investigated. Several fracture criteria have beenproposed in order to determine...