Time dependent crack growth in ceramic matrix composites with creeping fibers
- Univ. of California, Santa Barbara, CA (United States). Mechanical and Environmental Engineering Dept.
- Rockwell Science Center, Thousand Oaks, CA (United States)
Crack growth in ceramic matrix composites with creeping fibers has been investigated using a time dependent bridging law to describe the effect of fibers bridging a matrix crack. The fibers were assumed to creep linearly and the matrix was assumed to be elastic. Time dependent crack growth was predicted assuming that matrix crack growth occurs when the stress intensity factor at the matrix crack tip reaches a constant critical value. Crack growth rates are presented as a function of crack length and time. Domains of stable and unstable crack growth are outlined. The solutions illustrate the stable crack growth consists of a relatively brief period of deceleration followed by acceleration to large crack lengths, with crack velocity approaching constancy only at loads very near the matrix cracking stress and for very long cracks. Finally, the time needed to grow a long matrix crack is compared with a rough estimate for the time needed to rupture fibers. A transition is expected from life dominated by matrix crack growth at low stress to life dominated by fiber creep rupture after crack growth at higher stresses.
- DOE Contract Number:
- FG03-89ER45400
- OSTI ID:
- 131489
- Journal Information:
- Acta Metallurgica et Materialia, Journal Name: Acta Metallurgica et Materialia Journal Issue: 11 Vol. 43; ISSN 0956-7151; ISSN AMATEB
- Country of Publication:
- United States
- Language:
- English
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