Delayed failure under static fatigue of Hi-Nicalon bundles: The role of stress dispersion on scale effect

SiC-fibers are subjected to a predictable premature failure, consequence of slow crack growth mechanism. This has chiefly been studied through static fatigue testing multifilament tows. The discrepancy existing between experimental results, broadly dispersed, and the bundle theory (solely considering filament strength distribution) interpreted by discrete stochastic phenomena. In this work, uncertainty on applied stress caused fiber misalignment (slack) was rather investigated Monte Carlo simulation, ascribing each tow among established distributions. If coherent lifetime range could way be obtained, scale effect exponent also revealed: equal 12.6 it falls 8.4 bundle, in agreement with results. same would apply larger (woven tow).