### Abstract

In this paper we consider the problem of a functionally graded coating bonded to a homogeneous substrate with a partially insulated interface crack between the two materials subject to both thermal and mechanical loading. The problem is solved under the assumption of plane strain and generalized plane stress conditions. The heat conduction and the plane elasticity equations are converted analytically into singular integral equations which are solved numerically to yield the temperature and the displacement fields in the medium as well as the crack tip stress intensity factors. A crack-closure algorithm recently developed by the authors is applied to handle the problem of having negative mode I stress intensity factors. The Finite Element Method was additionally used to model the crack problem and to compute the crack-tip stress intensity factors. The main objective of the paper is to study the effect of the material nonhomogeneity parameters, partial insulation of the crack surfaces and crack-closure on the crack tip stress intensity factors for the purpose of gaining better understanding of the thermo-mechanical behavior of graded coatings.

Original language | English |
---|---|

Pages (from-to) | 139-162 |

Number of pages | 24 |

Journal | International Journal of Fracture |

Volume | 123 |

Issue number | 3-4 |

DOIs | |

Publication status | Published - Oct 2003 |

Externally published | Yes |

### Fingerprint

### Keywords

- Crack-closure
- Functionally graded coating
- Partially insulated crack
- Stress intensity factors

### ASJC Scopus subject areas

- Mechanics of Materials
- Computational Mechanics

### Cite this

*International Journal of Fracture*,

*123*(3-4), 139-162. https://doi.org/10.1023/B:FRAC.0000007373.29142.57

**Stress intensity factors for an interface crack between a functionally graded coating and a homogeneous substrate.** / El-Borgi, Sami; Erdogan, F.; Hatira, F. Ben.

Research output: Contribution to journal › Article

*International Journal of Fracture*, vol. 123, no. 3-4, pp. 139-162. https://doi.org/10.1023/B:FRAC.0000007373.29142.57

}

TY - JOUR

T1 - Stress intensity factors for an interface crack between a functionally graded coating and a homogeneous substrate

AU - El-Borgi, Sami

AU - Erdogan, F.

AU - Hatira, F. Ben

PY - 2003/10

Y1 - 2003/10

N2 - In this paper we consider the problem of a functionally graded coating bonded to a homogeneous substrate with a partially insulated interface crack between the two materials subject to both thermal and mechanical loading. The problem is solved under the assumption of plane strain and generalized plane stress conditions. The heat conduction and the plane elasticity equations are converted analytically into singular integral equations which are solved numerically to yield the temperature and the displacement fields in the medium as well as the crack tip stress intensity factors. A crack-closure algorithm recently developed by the authors is applied to handle the problem of having negative mode I stress intensity factors. The Finite Element Method was additionally used to model the crack problem and to compute the crack-tip stress intensity factors. The main objective of the paper is to study the effect of the material nonhomogeneity parameters, partial insulation of the crack surfaces and crack-closure on the crack tip stress intensity factors for the purpose of gaining better understanding of the thermo-mechanical behavior of graded coatings.

AB - In this paper we consider the problem of a functionally graded coating bonded to a homogeneous substrate with a partially insulated interface crack between the two materials subject to both thermal and mechanical loading. The problem is solved under the assumption of plane strain and generalized plane stress conditions. The heat conduction and the plane elasticity equations are converted analytically into singular integral equations which are solved numerically to yield the temperature and the displacement fields in the medium as well as the crack tip stress intensity factors. A crack-closure algorithm recently developed by the authors is applied to handle the problem of having negative mode I stress intensity factors. The Finite Element Method was additionally used to model the crack problem and to compute the crack-tip stress intensity factors. The main objective of the paper is to study the effect of the material nonhomogeneity parameters, partial insulation of the crack surfaces and crack-closure on the crack tip stress intensity factors for the purpose of gaining better understanding of the thermo-mechanical behavior of graded coatings.

KW - Crack-closure

KW - Functionally graded coating

KW - Partially insulated crack

KW - Stress intensity factors

UR - http://www.scopus.com/inward/record.url?scp=0742267654&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0742267654&partnerID=8YFLogxK

U2 - 10.1023/B:FRAC.0000007373.29142.57

DO - 10.1023/B:FRAC.0000007373.29142.57

M3 - Article

VL - 123

SP - 139

EP - 162

JO - International Journal of Fracture

JF - International Journal of Fracture

SN - 0376-9429

IS - 3-4

ER -