On the fracture behaviour of an interface crack with plastic zone corrections

•Elastic–plastic interface crack problem is studied by the mixed-mode Dugdale model.•Plastic zone size doesn’t depend on the Dundurs’ parameter α.•Plastic zone size is asymmetrical about the axial β = 0.•The relationships between PZS, CTOD and β are fitted by two functions.

In this paper, the mixed-mode Dugdale model is extended to investigate an interface crack problem. The plastic zone size and the crack tip opening displacement for an interface crack between two dissimilar materials under remote uniform tensile loading are examined. In the solution procedure, continuously distributed edge dislocations are applied to simulate the crack, and the physical problem is formulated into the singular integral-equation of 2nd kind. In the numerical examples, the effects of the normalized uniform tensile loads and the Dundurs’ parameters β on the normalized plastic zone size and the normalized crack tip opening displacement are analyzed in detail. The obtained results show that the normalized plastic zone size and the normalized crack tip opening displacement are symmetrical about the axis β = 0. Further, the relationships among the plastic zone size, the crack tip opening displacement and Dundurs’ parameters are curve-fitted as two polynomial functions which are highly user-friend for engineers in solving practical interface crack problems.