PSI - Issue 28

Domenico Ammendolea et al. / Procedia Structural Integrity 28 (2020) 1981–1991 Ammendolea et Al./ Structural Integrity Procedia 00 (2019) 000–000

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Fig. 7. Case 2: A schematic of a pre-cracked plate with an off-center hole. (a) a schematic of the geometry and boundary conditions (b) Initial mesh configuration

Fig. 8. Case 2: Comparison of crack paths between the present method and the results reported in (Rashid 1998) for an (a) intermediate stage and (b) the final stage of the propagation process

The proposed method is now applied for simulating crack propagation in composite materials. The plate in Fig. 7 a was examined by replacing the hole with an inclusions of different material (Fig. 9-a). In particular, the mismatch p m r E E  between the Young’s Modulus of the inclusion ( p E ) and plate ( m E ) has been used to define the mechanical properties of the system. A similar case has been investigated by Bouchard et al. (Bouchard et al. (2003)), which have observed different crack trajectories for variable mismatch values. In general, crack trajectories develop through the inclusion as r reduces, and vice versa. Fig. 9-b reports the crack trajectories gained by the proposed method. In addition, the crack trajectory of Fig. 8 ( i.e. the plate with the hole) is reported for comparison. The results are in accordance with the conclusions of Bouchard et al. , thus confirming the ability of the proposed method also to predict crack evolution in composite materials. As a matter of fact, the crack propagates through the inclusion with reduced values of r ( i.e. 0.2, 0.5 r  ). In this context, the case of the plate with the hole represents the extreme case. For 2 r  ( i.e. hard inclusion), the crack path keeps almost horizontal during propagation.