On the accuracy of the Cruse-Besuner weight function approximation for two-dimensional cracks

The Cruse-Besuner method for calculating energy release rates or weighted stress intensity factors for semi-elliptical surface cracks is based on some assumptions. To check the accuracy of this method an internal elliptical crack under roof-shaped stress distribution is considered. The deviations from the exact solution are in the order of about 3%. From these results also for surface cracks in bending the same accuracies can be expected.

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Résumé On sait que la méthode de Gruse-Besuner pour le calcul des vitesses de relaxation de l'énergie ou des facteurs pondérés d'intensité de contraintes relatifs à des fissures de surface semi-elliptiques est basée sur certaines hypothèses.En vue de vérifier la précision de cette méthode, on considère une fissure elliptique interne soumise à une distribution triangulaire de contraintes. On constate que les écarts par rapport à la solution exacte sont de l'ordre de 3%.A partir de ces résultats, on peut s'attendre à une précision semblable pour des fissures de surface soumises à contraintes de flexion.

     

Stress intensity factors for semi-elliptical surface cracks in a plate under tension based on the Isida's solution

The stress intensity factor solution given by Isida et al. for semi-elliptical surface cracks in plates is improved and extended. The data tabulated for the ranges 0a/t0.6 and 0.25a/c1.0 were checked using the energy relation and found to be superior to solutions available in the literature.     

T-stress and crack path stability of DCDC specimens

The T-stress term of DCDC specimens is computed using the Boundary Collocation procedure and limit case consideratons. This parameter allows to understand path stability as found in literature for subcritical crack growth in galss.