## Abstract

Plane strain asymptotic stress and strain fields near the tip of a crack growing quasi-statically along the interface of a linear elastic and an incompressible elastic power law creeping material is studied. The solutions for the stress and strain fields are found to be in the separable forms, γ_{ij}, ∼ a ̇ BE_{+r}^{ 1 (n-1)} γ ̃ij(θ,n,β) and ε{lunate}ij ∼ a ̇ BE_{+r}^{ 1 (n-1)} ε{lunate} ̃ij(θ,n,β), whenn ≥ 3. Heren and B are the power law creeping exponent and coefficient respectively, E_{+} and E_{-} are moduli of elasticity of the elastic-creeping and elastic materials, β = E_{+} E_{-}, r is the radial distance from the moving tip and θ is the angle measured from the interface. The amplitude of the field is determined by the crack tip velocity, a, and material parameters. The angular functions \ ̃gs_{ij}(θ, n, β) and \ ̃ge_{ij} exhibit only two modes, one of which is close to pure mode I and the other one is close to pure mode II ; arbitrary mode mixity cannot be prescribed. For a given β, there is a corresponding n, close to n = 3, at which the two solutions coalesce into one. Below this value of n no real separable solution exists. We also studied the special case of a quasi-statically growing crack in a homogeneous elastic power law creeping material. We find that only pure modes I and II are possible near the tip, and the amplitude of the field is determined by a and material parameters. Thus the near tip field is independent of the far field loading conditions for both the bi-material and the homogeneous cases. For 1≤n< 3, the elastic strain dominates the creep strain so that the near tip stress field of the growing interface crack is given by the classical bimaterial complex K field and therefore has an oscillatory singularity. The complex K in this case depends not only on the specimen geometry and the applied load, but also on the crack growth history.

Original language | English (US) |
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Pages (from-to) | 181-214 |

Number of pages | 34 |

Journal | Journal of the Mechanics and Physics of Solids |

Volume | 42 |

Issue number | 2 |

DOIs | |

State | Published - Feb 1994 |

Externally published | Yes |

## ASJC Scopus subject areas

- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering