Numerical simulations of crack tip stress-strain fields in single crystal nickel-base superalloys at high temperature under creep-fatigue loadings
| Autor: | Marchal, N., Flouriot, S., Samuel Forest, Remy, L. |
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| Přispěvatelé: | Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | ICF 11 International conference of fracture International conference of fracture, 2005, Turin, Italy. 6 p Scopus-Elsevier |
| Popis: | International audience; This work deals with the finite element analysis of cracks in single crystal Nickel-base superalloys. The first part consists in the computation of stress and strain fields at the tip of a static crack in a CT specimen. After a presentation of these crack tip fields in single crystals (Rice [1], Flouriot et al [2]), two-dimensional (001)[110] CT specimens subjected to creep-fatigue (mode I) loading are simulated. The slip systems activity at the crack tip is studied. The slip activity along the front localisation band is plotted as a function of the distance from the crack tip. Stress and strain are analysed at different points as a function of time. Then activity of slip systems is compared to the one obtained with pure creep or pure fatigue loadings, and the importance of dwell times is shown. The second part deals with the influence of the wake plastic zone on the crack tip fields. The goal is to study the influence of precraking on the crack tip fields. The crack propagation is simulated using an uncoupled node-release technique. The load is calculated so that a decreasing DK is applied during precracking. Then, a monotonic loading is applied and the activity of slip systems is studied around the crack tip. This result is then compared to the one obtained without precracking. This study of crack tip fields will contribute to the formulation of a crack propagation model based on local approach to fracture. |
| Databáze: | OpenAIRE |
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