Fracture Propagation in Brazilian Discs with Multiple Pre-existing Notches by Using a Phase Field Method

The crack propagation in the Brazilian discs with multiple pre-existing notches is investigated by using a phase field method. The phase field modeling is verified by applying a direct tension test and an indirect splitting test on a Brazilian specimen with no pre-existing notches where the simulated results are in good agreement with previous numerical and experimental results. The influence of the notch number and spacing on the crack propagation in the Brazilian discs with multiple vertically and horizontally arranged notches is studied. Outer cracks initiate from the notch tips and propagate at a small angle with the vertical direction, finally coalescing with the ends of the discs. The strength of the specimen decreases as the notches increases. The Brazilian discs with horizontally arranged pre-existing notches only have outer cracks when the notch number is 1, 3, and 5 and have both outer and inner cracks for two and four notches. The peak load of the Brazilian discs with horizontally arranged notches increases as the notch spacing increases. The final crack patterns obtained by the phase field modeling are consistent with those by previous numerical simulations and experimental tests.