Nonuniform ferroelastic domain switching driven by two-parameter crack tip stress field

This paper addresses a nonuniform ferroelastic domain switching model driven by two-parameter crack tip stress field. The model is applied to analyze the effect of transverse stress (T-stress) on switching zone geometry and switch induced toughening. It is concluded that: (1) The sign and magnitude of T-stress influence switching zone size but not its shape. (2) Tensile T-stress decreases switch toughening, while compressive T-stress increases it. As an example, the analytical result of switch toughening is used to interpret the test dependency of R-curve. Predictions are in agreement with experimental results of two types of tests of ferroelectrics.

► T-stress bears effect on switching zone geometry and ferroelastic switch toughening.
► T-stress influences the size but not the shape of mono-domain switching zone.
► T-stress decreases or increases the switching zone size, which depends on its sign.
► Tensile T-stress weakens the toughening, while compressive T-stress strengthens it.
► Based on our uniform switching criterion, a logarithmic-type toughening is obtained.