Abstract
A computationally-efficient numerical approach to treating matrix nonlinearity in ceramic matrix composite components has been developed and validated. The model employs a dual mesh comprising strings of line elements that represent the fiber tows and 3D effective medium elements that define the external geometry and embody the matrix-dominated properties. Validation addressed test data for unnotched and open-hole tension specimens. For these tests, the onset of nonlinearity and subsequent plasticity due to matrix microcracking and interfacial debonding and sliding are satisfactorily represented by a linear Drucker-Prager model for failure initiation in the effective medium along with a fully-associated flow rule with isotropic, perfectly-plastic flow. Composite failure is assumed to be correlated with the maximum local stress averaged over a gauge volume dictated by the fiber tow width. Using one set of specimens for calibration, very good predictions of the nonlinear stress-strain response and ultimate strength of other specimens are obtained.
Original language | English (US) |
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Pages (from-to) | 222-229 |
Number of pages | 8 |
Journal | Composites Part A: Applied Science and Manufacturing |
Volume | 41 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2010 |
Keywords
- A. Ceramic-matrix composites (CMCs)
- B. Fracture
- B. Stress concentrations
- C. Finite element analysis (FEA)
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials