Spherical indentation of compositionally graded materials: Theory and experiments
Computational and experimental results on the evolution of stresses and deformation fields due to indentation from a rigid spherical indenter on a graded substrate are presented. The analyses address the variations in Young's modulus, E, of the substrate as a function of depth, z, beneath the i...
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Published in | Acta materialia Vol. 45; no. 4; pp. 1307 - 1321 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.04.1997
Elsevier Science |
Subjects | |
Online Access | Get full text |
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Summary: | Computational and experimental results on the evolution of stresses and deformation fields due to indentation from a rigid spherical indenter on a graded substrate are presented. The analyses address the variations in Young's modulus,
E, of the substrate as a function of depth,
z, beneath the indented surface for an exponential law,
E =
E
0e
αz
, where
E
0 is Young's modulus at the surface and
1
α
is a length parameter. The finite element simulations are used to check the analytical theory of Giannakopoulos and Suresh [
Int. J. Solids Struct. (in press)], and are used to gain further insights into the effects of the variation in Poisson ratio,
v, with depth. The theoretically predicted force-indenter penetration (
P-h) curves are also compared with direct experimental measurements made on compositionally graded NiAl
2O
3 and TiAlY
2O
3-stabilized TZP composites of known composition gradients. A new method is proposed for the estimation of Young's modulus variations through a compositionally graded layer by recourse to spherical indentation. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1359-6454 1873-2453 |
DOI: | 10.1016/S1359-6454(96)00291-1 |