## Abstract

Fracture of quasi‐brittle materials such as ceramics and cement‐based materials can be described by an R‐curve, defined as fracture resistance. The R‐curve can be constructed as the envelope of the strain energy release rates (G). In this study, R‐curve is defined as an envelope of G‐curves obtained by varying the dimensions of identical specimens, while keeping the geometry and the initial flaw size constant. By approximating the G‐curve with a second‐order function of the crack length, a simple formulation of the R‐curve is derived by solving a differential equation. Three parameters are needed for the proposed R‐curve. These parameters can be obtained by testing a notched‐beam specimen and using linear elastic fracture mechanics. The proposed R‐curve simulates well the geometry dependency as well as other characteristics of the fracture response of quasi‐brittle materials.

Original language | English (US) |
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Pages (from-to) | 2831-2836 |

Number of pages | 6 |

Journal | Journal of the American Ceramic Society |

Volume | 74 |

Issue number | 11 |

DOIs | |

State | Published - Nov 1991 |

## Keywords

- R curve
- brittle materials
- cements
- cracks
- models

## ASJC Scopus subject areas

- Ceramics and Composites
- Materials Chemistry