Crack deflection by the transformable particles dispersed in composites

The crack deflection in transformable particle-reinforced composites is studied in the present paper.The contribution of phase transformation on the crack tip J_k-integral (k = 1, 2) is explicitly determined bythe material configurational theory. For the crack deflection angle from its original crack path induced by thephase transformation it can be shown that the crack initiates in the direction along which the potential energyrelease rate in terms of the crack tip J_k-integral possesses a stationary (maximum) value. The influence of oneindividual particle near the crack tip on the crack deflection is studied by accounting for both dilatant and sheartransformation components. Furthermore, an FEM method is developed to model the stress-induced phasetransformation on the basis of a macroscopic phenomenological constitutive model where multiple particlesare taken to be non-uniformly distributed in a matrix.Numerical simulations are performed to observe the crackdeflection by a cluster of particles. The results show a significant non-symmetric stress distribution locally atthe crack tip, causing the crack to deflect. It is found that regions in the material with a higher volume fractionof transformable particles tend to deflect the crack growth more.