Delayed failure under static fatigue of Hi-Nicalon bundles: The role of stress dispersion on scale effect
Language
EN
Article de revue
This item was published in
Materials Letters. 2021, vol. 294, p. 129806
English Abstract
SiC-fibers are subjected to a predictable premature failure, consequence of a slow crack growth mechanism. This has chiefly been studied through static fatigue testing of multifilament tows. The discrepancy existing between ...Read more >
SiC-fibers are subjected to a predictable premature failure, consequence of a slow crack growth mechanism. This has chiefly been studied through static fatigue testing of multifilament tows. The discrepancy existing between experimental results, broadly dispersed, and the bundle theory (solely considering the filament strength distribution) has been interpreted by discrete stochastic phenomena. In this work, the uncertainty on applied stress caused by fiber misalignment (slack) was rather investigated through Monte Carlo simulation, ascribing to each filament of the tow a strength and a stress among established distributions. If a coherent lifetime range could this way be obtained, a scale effect on stress exponent was also revealed: equal to 12.6 on filament it falls to 8.4 on bundle, in agreement with experimental results. The same would apply to larger scale (woven tow).Read less <
English Keywords
Hi-Nicalon
Slow crack growth
Static fatigue
Scale effect