Abstract
A number of current practices in fracture mechanics which use quantities near a crack tip to make conclusions about response at the crack tip itself are examined. Specifically these include: stress and displacement matching to estimate stress intensity factors, monitoring local stress and strain values to predict fracture, and both crack opening angle and crack opening displacement as fracture criteria. By means of a pair of counter applications, all of these procedures are demonstrated to have the potential of leading to completely incorrect conclusions. An understanding of what causes this inadequate performance then indicates that such procedures may be unreliable in general and prompts suggestions as to alternatives.
Résumé
On examine diverses pratiques courantes en Mécanique de Rupture qui font usage de grandeurs paramétriques au voisinage de l'extrémité d'une fissure pour tirer des conclusions sur ce qui se passe à cette extrémité même. Ces grandeurs sont notamment: les valeurs de la contrainte et du déplacement correspondant à un facteur d'intensité de contrainte estimé, l'enregistrement des contraintes et déplacements locaux en vue de prédire la rupture, et l'angle et le déplacement d'ouverture d'une fissure en tant que critères de rupture.
En considérant une paire d'applications divergentes, on démontre que toutes ces procédures risquent d'entraîner des conclusions complètement incorrectes.
Une analyse des causes de ces inadéquations montre que ces procédures peuvent se révéler peu fiables en général, et conduit à des suggestions de procédures alternatives.
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Sinclair, G.B. Some inherently unreliable practices in present day fracture mechanics. Int J Fract 28, 3–16 (1985). https://doi.org/10.1007/BF00033698
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DOI: https://doi.org/10.1007/BF00033698