The role of continuous microcrack nucleation on the fracture behavior of ceramics and ceramic composites

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:175372

Biner, S B ^[1]

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1. Iowa State Univ., Ames, IA (United States)

The role of continuous microcrack nucleation on the crack growth behavior in brittle microcracking solids and composites was numerically investigated. The random nucleation, orientation and size effects of discrete microcracks and resulting interaction of stress-strain fields are fully accounted for in a hybrid finite element model. The results indicate that the energy expenditure due to microcrack nucleation does not contribute significantly to the resistance to crack growth. The contribution of elastic interactions of microcracks with the main crack to the toughening behavior is strongly influenced by the density of nucleated microcracks with the extent of the nucleation. It is shown that the size of microcrack nucleating microstructural features could effect these two parameters in opposite ways, leading to the presence of a critical microstructural length scale for the maximum toughening behavior. In the case of the composites, it is observed that the interaction of the main crack with the stress fields created by the reinforcing phase, rather than the interaction of microcracks, can be controlling parameter for the resistance to crack growth even in the presence of a large population of microcracks.

• OSTI ID: 175372
• Report Number(s): CONF-950686--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERAMICS
COMPOSITE MATERIALS
CRACKS
FRACTURE PROPERTIES
MATHEMATICAL MODELS
SIZE
STRESSES