Microcrack toughening in two-phase multilayered media
- Ohio State Univ., Columbus, OH (United States)
This work presents a numerical model of the toughening behavior exhibited when a Mode I macrocrack propagates through alternating tough and brittle layers of a composite. The toughening occurs due to microcracking in brittle layers. Microcracks form at periodic flaw sites in brittle layers when the stress at a site is sufficient to propagate a crack within the layer. An established microcrack is modeled by a dislocation dipole, with Burgers vector chosen to render the normal component of stress equal to zero at the dipole midpoint. R-curves for layered media are predicted as a function of bi-layer thickness, volume fraction, density of flaw sites, and inhomogeneity in fracture toughness and elastic modulus. A critical combination of properties for the onset of R-curve behavior is identified, and features which optimize the upper plateau of the R-curve are discussed in light of experimental observations.
- OSTI ID:
- 665194
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 15 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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