Crack Paths 2009

An interesting feature to point out is the influence of the T-stress on the kink angle. It is

almost 90 deg. if the crack grows in the stiff layer whereas it does not exceed 50 deg. if

the crack grows in the compliant one. It can be compared to the fracture pattern of a

laminated ceramic (figure 3) made of compliant (light) and stiff (dark) layers [16].

However, the comparison has its limits since there are no large deflections of the crack

along the interface as assumed in the present analysis (figure 2).

Figure 3. Schematic fracture pattern of a laminated ceramic

For a complete analysis the competition between the deflection mechanism and the

delamination growth should be analysed. This requires the knowledge of the interface

commonly admitted

is nd o the mix ty of modes [7,8] involved at the in erface crac

toughness and strength, which determination is difficult since it

that they depe

k tip.

R E F E R E N C E S

notch. 1. 1. Leguillon D. (2002). Strength or toughness? A criterion for crack onset at a

Eur. J. Mech. A/Solids, 21, 61–72.

. Leguillon D. (2003). Computation of 3D singular elastic fields for the prediction of

2 failure at co

rners, in “Advances in Fracture and damage Mechanics”, Key

Engineering Materials, vol. 251-252, 147-152.

3. Leguillon D., Sanchez-Palencia E. (1987). Computation of singular solutions in

iley, New-YorkMasson, Paris.

elliptic problems and elasticity. J. W

4. Rice J R (1988). Fracture mechanics concepts for interfacial cracks. J. Appl. Mech.,

55, 98–103.

ure mechanics – Application to the 5. Leguillon D., Siruguet K. (2001). Finite fract onset f a crack at a bimaterial corner. In IUTAMSymposium on An lytical and

aterials, B.L. Computational Fracture Mechanics of Non-Homogeneous M Karihaloo ed., Solid M chani s and its Applications vol.97, Kluw Academic

Publishers, D

ordrecht, 2002, 11-18.

6. Leguillon D. (1989). Calcul du taux de restitution de l’énergie au voisinage d’une

singularité, C.R. Acad. Sci. Paris, série II, 945-950.

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