Interfacial cracks in plates: A three-dimensional numerical investigation

• Published in: International journal of solids and structures 1993, Vol.30 (22), p.3139-3158
• Main Authors: Lee, Yeong Joo, Rosakis, A.J.
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fundamental areas of phenomenology (including applications); Physics; Solid mechanics; Structural and continuum mechanics
• ISSN: 0020-7683; 1879-2146
• DOI: 10.1016/0020-7683(93)90144-V

The three-dimensional field at a crack front in a bimaterial interface is investigated in order to identify relevant fracture parameters in thin plate laboratory specimens. Existence of plane stress K-dominance is necessary for the proper analysis of experimental data, which can be obtained directly from the crack-tip field by optical methods. The analysis of the three-dimensional structure of the crack-tip field presented here is performed in relation to the three-point bend specimen geometry used in the experiments described in Lee and Rosakis (1993), Interfacial cracks in plates: an experimental investigation (in preparation). It is well known that the three-dimensional field at the vicinity of a crack in a plate composed of a homogeneous material extends over a half-plate thickness from the crack front. However in a bimaterial fracture specimen, in addition to the singular field at the crack tip, mismatch of material properties along the interface induces a strip of three-dimensionality extending along the bimaterial interface ahead of the crack tip. The extent of the three-dimensional zone and a critical discussion of the zone of K-dominance are presented. The relation between the stress intensity factors in the remote plane stress K-field and the stress intensity factors inside the near-tip plane strain K-field is also derived by means of a separate boundary-layer type of numerical analysis. Finally, a means of scaling the results obtained by experimentation in thin plate specimens of a specific thickness-to-plate specimens of any thickness is proposed.