Three-dimensional simulation of crack propagation in ferroelectric polycrystals: Effect of combined toughening mechanisms

We simulate the fracture processes of ferroelectric polycrystals in
three dimensions using a phase-field model. In this model, the grain
boundaries, cracks and ferroelectric domain walls are represented in a
diffuse way by three phase-fields. We thereby avoid the difficulty of
tracking the interfaces in three dimensions. The resulting model can
capture complex interactions between the crack and the polycrystalline
and ferroelectric domain  microstructures. The simulation results show
the effect of the microstructures on the fracture response of the
material. Crack deflection, crack bridging, crack branching and
ferroelastic domain switching are observed to act as the main fracture
toughening mechanisms in ferroelectric polycrystals. Our fully 3-D
simulations illustrate how the combination of these mechanisms enhances
the fracture toughness of the material, and pave the way for further
systematic studies, including fracture homogenization.

http://www.sciencedirect.com/science/article/pii/S1359645413008665