Polycrystalline microstructure, cubic elasticity and nucleation of high-cycle fatigue cracks - CEA - Commissariat à l’énergie atomique et aux énergies alternatives Access content directly
Journal Articles International Journal of Fracture Year : 2006

Polycrystalline microstructure, cubic elasticity and nucleation of high-cycle fatigue cracks

Abstract

It is well-known that high-cycle fatigue cracks usually nucleate in surface well-oriented grains with a high Schmid factor. A numerical evaluation of the effect of crystalline elasticity anisotropy (which is often neglected) on the stress state in well-oriented grains is presented. Each of these grains is located at the free surface of an aggregate. The other crystallographic orientations are random. Numerous finite element computations are carried out for evaluating the effect of the neighboring grain orientations. Resolved shear stress and normal stress averages are given, as well as scatter parameters and histograms. Several metals, orientations, and loading conditions are considered. For common (anisotropic) metals/alloys such as copper and austenitic steels, the local average resolved shear stress is about 18% smaller than the macroscopic value which induces a Schmid factor value with respect to the macroscopic tensile stress of 0.41 instead of the classical 0.5 value. Relative scatters in resolved shear stress and corresponding normal stress are high (respectively ±22% and ±38%). These high scatter values computed for small applied loads can explain many observations taken from the literature showing a large scatter in the plastic slip line feature, dislocation microstructure, microstructurally short crack nucleation, and propagation rate among well-oriented surface
Fichier principal
Vignette du fichier
200700000926.pdf (657.73 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

cea-02511911 , version 1 (19-03-2020)

Identifiers

Cite

Maxime Sauzay, Thomas Jourdan. Polycrystalline microstructure, cubic elasticity and nucleation of high-cycle fatigue cracks. International Journal of Fracture, 2006, 141 (3-4), pp.431-446. ⟨10.1007/s10704-006-9005-x⟩. ⟨cea-02511911⟩
29 View
170 Download

Altmetric

Share

Gmail Facebook X LinkedIn More