### Abstract

An R-curve approach for fracture of quasi-brittle materials is proposed in this paper. An R-curve is defined as an envelope of fracture energy release rate of specimens with different sizes but the same initial notch length. By assuming that an effective traction-free critical crack is the function of an initial crack length contained in a material, an expression of the R-curve with two parameters can be derived by solving a differential equation. The parameters of the R-curve can be uniquely determined according to K_{IC}
^{S} and CTOD_{c} for positive geometry specimens, and according to K_{IC}
^{S} and dK_{1}/da = 0 for negative geometry specimens. Load-CMOD and loaddisplacement response can be predicted based on the proposed R-curve by requiring that the crack driving force and crack growth resistance are equal at every equilibrium crack length. The predicted curves show a good agreement with the wide range of experimental results. Pre-critical stable crack propagation of quasi-brittle materials can be well described by the present approach.

Original language | English (US) |
---|---|

Pages (from-to) | 901-913 |

Number of pages | 13 |

Journal | Engineering Fracture Mechanics |

Volume | 37 |

Issue number | 4 |

DOIs | |

State | Published - 1990 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Mechanical Engineering
- Mechanics of Materials

### Cite this

*Engineering Fracture Mechanics*,

*37*(4), 901-913. https://doi.org/10.1016/0013-7944(90)90087-W

**An r-curve approach for fracture of quasi-brittle materials.** / Chengsheng, Ouyang; Mobasher, Barzin; Surendra P., Shah.

Research output: Contribution to journal › Article

*Engineering Fracture Mechanics*, vol. 37, no. 4, pp. 901-913. https://doi.org/10.1016/0013-7944(90)90087-W

}

TY - JOUR

T1 - An r-curve approach for fracture of quasi-brittle materials

AU - Chengsheng, Ouyang

AU - Mobasher, Barzin

AU - Surendra P., Shah

PY - 1990

Y1 - 1990

N2 - An R-curve approach for fracture of quasi-brittle materials is proposed in this paper. An R-curve is defined as an envelope of fracture energy release rate of specimens with different sizes but the same initial notch length. By assuming that an effective traction-free critical crack is the function of an initial crack length contained in a material, an expression of the R-curve with two parameters can be derived by solving a differential equation. The parameters of the R-curve can be uniquely determined according to KIC S and CTODc for positive geometry specimens, and according to KIC S and dK1/da = 0 for negative geometry specimens. Load-CMOD and loaddisplacement response can be predicted based on the proposed R-curve by requiring that the crack driving force and crack growth resistance are equal at every equilibrium crack length. The predicted curves show a good agreement with the wide range of experimental results. Pre-critical stable crack propagation of quasi-brittle materials can be well described by the present approach.

AB - An R-curve approach for fracture of quasi-brittle materials is proposed in this paper. An R-curve is defined as an envelope of fracture energy release rate of specimens with different sizes but the same initial notch length. By assuming that an effective traction-free critical crack is the function of an initial crack length contained in a material, an expression of the R-curve with two parameters can be derived by solving a differential equation. The parameters of the R-curve can be uniquely determined according to KIC S and CTODc for positive geometry specimens, and according to KIC S and dK1/da = 0 for negative geometry specimens. Load-CMOD and loaddisplacement response can be predicted based on the proposed R-curve by requiring that the crack driving force and crack growth resistance are equal at every equilibrium crack length. The predicted curves show a good agreement with the wide range of experimental results. Pre-critical stable crack propagation of quasi-brittle materials can be well described by the present approach.

UR - http://www.scopus.com/inward/record.url?scp=0025595191&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025595191&partnerID=8YFLogxK

U2 - 10.1016/0013-7944(90)90087-W

DO - 10.1016/0013-7944(90)90087-W

M3 - Article

AN - SCOPUS:0025595191

VL - 37

SP - 901

EP - 913

JO - Engineering Fracture Mechanics

JF - Engineering Fracture Mechanics

SN - 0013-7944

IS - 4

ER -