
[article]
Titre : |
Micromechanics and energetics of the single-fiber composite fragmentation phenomenon |
Type de document : |
texte imprimé |
Auteurs : |
Daniel H. Wagner, Auteur ; Xio-Feng Zhou, Auteur |
Année de publication : |
1997 |
Article en page(s) : |
p. 107-117 |
Note générale : |
Bibliogr. |
Langues : |
Français (fre) |
Catégories : |
Cisaillement (mécanique) Composites à fibres de verre Résistance des matériaux
|
Tags : |
'Résistance au cisaillement' 'Composite à fibre simple' 'Liaison Fibre-matrice' 'Fibre multi-fragmentation' de E-verre' |
Index. décimale : |
668.4 Plastiques, vinyles |
Résumé : |
The quality of the fiber-matrix bonding in composites is traditionnally quantified using the interfacial shear strength, based on measurements made using micromechanical tests. However, it has gradually appeared that this parameter is both ambiguous in terms of its physical meaning and, at the same time, difficult to measure reliably in many cases. Also, different micromechanical techniques yield differing values of the interfacial shear strength and moreover, it has been suggested in a few studies that it may not be the critical factor governing fiber-matrix debonding. Here an energy-balance approach is proposed, by which the degree of fiber-matrix bonding is now quantified by a new measurable parameter, the interfacial energy. This latter is a functionof the fiber geometrical and mechanical characteristics, the stress transfer length, and the debonding length. The validity of the approach is discussed in the case of the single-fiber composite test, in which progressive fragmentation of a single brittle fiber in a more ductile polymeric matrix takes place, using data for E-glass fibers embedded in a polymer matrix. We use a microcomposite specimen that comprises two identical single fibers within a thin polymeric film. The fibers are embedded parallel to each other, at a distance sufficiently large for fiber-fiber interactions or perturbations to be negligible. One of the fibers is pre-loaded at its ends prior to (and during) matrix polymerization, whereas the other fiber experiences only typical thermal residual stresses due to specimen preparation. A continuously monitored tensile fragmentation test is performed, and the results are discussed using an energy balance approach. The fiber fragmentation patterns observed in both fibers, as well as the calculated interface energies from both fibers, are found to differ significantly. These observations and conclusions give rise to fundamental questions and possible solutions regarding the meaning, interpretation, power, and accuracy of the fragmentation test. |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9536 |
in REVUE DES COMPOSITES ET DES MATERIAUX AVANCES > Vol. 7, N° Hors série (1997) . - p. 107-117
[article]
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