Analyses of interfacial shear debonding in fiber-reinforced ceramic composites
An important toughening mechanism in fiber-reinforced ceramic composites is pullout of fibers from the matrix during matrix cracking. This relies on mode II (i.e., shear) debonding at the fiber/matrix interface which can be analyzed using either the strength-based or the energy-based criterion. In the strength-based approach, debonding occurs when the maximum interfacial shear stress induced by the applied load reaches the interfacial shear strength, {tau}{sub s}. In the energy-based approach, a mode II crack propagating along the interface is considered, and debonding occurs when the energy release rate due to crack propagation reaches the interface debond energy, {Gamma}{sub 1}. Based on the above two criteria, the applied stress on the fiber to initiate debonding (i.e., the initial debond stress), {sigma}{sub d}, can be derived. The first issue considered in the present study is the relation between {tau}{sub s} and {Gamma}{sub 1}. Also, for a monolithic ceramic, the tensile strength can be related to its defect size based on the Griffith theory. A question is hence raised as to whether the initial debond stress for fiber pullout in a fiber-reinforced ceramic composite can be related to any defect at the interface.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 650365
- Report Number(s):
- ORNL/CP--96904; CONF-980717--; ON: DE98004961; BR: KC0201050
- Country of Publication:
- United States
- Language:
- English
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