ISSN:
1551-2916
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Maschinenbau
,
Physik
Notizen:
Monotonic and cyclic fatigue behavior of single fibers or fiber fabrics are of significant interest, since fiber assemblies or fiber-reinforced composite materials in structural applications are often subjected to cyclic loading. Studying the cyclic fatigue behavior of fibers is particularly difficult because of their small diameter (∼10 μm) and high aspect ratio. In this paper, we report results of monotonic tension and tension–tension fatigue behavior of two sol–gel-derived ceramic fibers: Al2O3–SiO2–B2O3 (Nextel 312) and Al2O3 (Nextel 610). Nextel 312 exhibited a great deal of variability in tensile strength, reflected by a Weibull modulus of 4.6, versus Nextel 610, which had a Weibull modulus of 10.5. Our experiments showed clearly that cyclic loading was more damaging than static loading and, thus, resulted in a lower cyclic fatigue life compared with static loading. The fracture behavior under fatigue loading was distinctly different from that under monotonic loading. It is believed that processing-induced flaws acted as crack initiation sites, and that the cyclic loading induced subcritical cracking, followed by coalescence of cracks immediately prior to failure.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1551-2916.2004.00007.x
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