## Abstract

This paper extends recent work done by the authors in modeling length scale-dependent damage behavior of ceramic matrix composites (CMCs) to include effects of local anisotropy introduced by matrix cracking. This model captures scale-dependent damage initiation and propagation behavior of the brittle matrix by employing internal state variable (ISV) theory within a multiscale modeling framework to obtain damaged matrix stress/strain constitutive relationships at each length scale. The damage ISV captures the effects of matrix cracking and growth by using fracture mechanics and the self-consistent scheme to determine the reduced stiffness of the cracked matrix. Matrix cracks, which activate when stress intensity factors near manufacturing induced cavities exceed the fracture toughness of the material, are assumed to be transversely isotropic in the plane of the crack, and matrix anisotropy occurs when the damaged stiffness tensor is rotated from the crack plane to the global axes. The crack progression and temporal evolution of the damage ISV are governed by fracture mechanics and crack growth kinetics. The model effectively captures first matrix cracking, which is the first significant deviation from linear elasticity. The nonlinear predictive capabilities of the material model are demonstrated for monolithic silicon carbide (SiC) and a 2D woven five-harness satin (5HS) carbon fiber SiC matrix (C/SiC) CMC.

Original language | English (US) |
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Title of host publication | TMS 2020 149th Annual Meeting and Exhibition Supplemental Proceedings |

Editors | Zhiwei Peng, Jiann-Yang Hwang, Jerome Downey, Dean Gregurek, Baojun Zhao, Onuralp Yucel, Ender Keskinkilic, Tao Jiang, Jesse White, Morsi Mahmoud |

Publisher | Springer |

Pages | 1499-1509 |

Number of pages | 11 |

ISBN (Print) | 9783030362959 |

DOIs | |

State | Published - 2020 |

Event | 149th Annual Meeting and Exhibition of the Minerals, Metals and Materials Society, TMS 2020 - San Diego, United States Duration: Feb 23 2020 → Feb 27 2020 |

### Publication series

Name | Minerals, Metals and Materials Series |
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ISSN (Print) | 2367-1181 |

ISSN (Electronic) | 2367-1696 |

### Conference

Conference | 149th Annual Meeting and Exhibition of the Minerals, Metals and Materials Society, TMS 2020 |
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Country/Territory | United States |

City | San Diego |

Period | 2/23/20 → 2/27/20 |

## Keywords

- Ceramic matrix composite
- Damage
- Fracture mechanics
- Internal state variable
- Multiscale

## ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Energy Engineering and Power Technology
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry