### Abstract

The role of free-edge stresses in controlling the initiation of failure from the interface corner of a scarf joint subjected to a uniform change in temperature is examined. In general, the stress field can be expressed by σ_{ij} = Hr^{λ-1} + σ_{ij0}, where r is the radial distance from the interface corner, λ - 1 is the order of the stress singularity, H is the intensity of the singularity- and σ_{ij0} is a non-singular constant stress. A combination of the finite element method and a path-independent integral is used to evaluate the magnitude of H for two joint configurations: (i) a scarf joint between two long bi-material strips; and (ii) a scarf joint consisting of a thin elastic layer sandwiched between two substrates. The magnitude of H is linearly dependent on a non-dimensional constant function a; the magnitude of a decreases with increasing level of mismatch in the elastic properties of the bonded materials. A comparison between the values of H evaluated by the path-independent integral method and the commonly used extrapolation method indicate that the extrapolation method could be in error by as much as 25%.

Original language | English |
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Pages (from-to) | 687-703 |

Number of pages | 17 |

Journal | Fatigue and Fracture of Engineering Materials and Structures |

Volume | 21 |

Issue number | 6 |

DOIs | |

Publication status | Published - 1 Jan 1998 |

### Keywords

- Bonded joints
- Failure criteria
- FEM
- Stress singularity
- Thermal stress