Effects of as-received defects on ceramic matrix composites properties using high-fidelity microstructures with periodic boundary conditions

Conference · Wed Dec 01 04:00:00 EST 2021

DOI:https://doi.org/10.12783/asc36/35838· OSTI ID:2395952

Khafagy, Khaled H. ^[1]; Chattopadhyay, Aditi ^[2]

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1. Arizona State Univ., Tempe, AZ (United States); Arizona State University
2. Arizona State Univ., Tempe, AZ (United States)

The presence of microstructural defects in as-received specimens of ceramic matrix composites (CMCs) significantly influences their constitutive response and damage, highlighting the importance of characterization and quantification of these defects for accurate assessment of damage and failure in the service environment. In a recent effort, the authors developed an algorithm to generate stochastic representative volume elements (SRVEs) of Carbon fiber Silicon-Carbide-Nitride matrix (C/SiNC) CMCs based on extensive multiscale material and defect characterization data. This paper implements this algorithm within a commercial finite element solver with periodic boundary conditions (PBCs) for high-fidelity micromechanics analysis and investigation of macroscopic material behavior of C/SiNC composites. Different loading directions are used to predict the global mechanical properties, and the results are in excellent agreement with theoretical (rule of mixture) predictions. Subsequently, the effects of as-received defects on the global and local responses are investigated. The results show that intratow porosity has pronounced degradation effects on the global elastic properties and results in complex stress localization patterns, which can be attributed to potential damage initiation sites.

• Research Organization: Arizona State University
• Sponsoring Organization: USDOE
• DOE Contract Number: FE0031759
• OSTI ID: 2395952
• Report Number(s): DOE-0031759; Journal Serial ID: 978-171383759-6
• Country of Publication: United States
• Language: English