Interface crack between two different viscoelastic media

The plane (including antiplane) problem of an interfacial crack between different viscoelastic (including viscoelastic and elastic) media is considered. By using the Laplace transform method, the viscoelastic problem is reduced to an associated elastic one. The corresponding elastic analysis results in the viscoelastic solutions in the transformed field. The crack tip fields and fracture parameters of the viscoelastic interface crack are derived through an approximate Laplace inverse transform method. As an example, numerical calculations for an interfacial crack between viscoelastic and elastic materials are carried out. It is shown that the simple formulae of the crack line (and tip) fields and fracture parameter (energy release rate) of the viscoelastic interface crack, derived by the approximate method, are quite accurate. When the bimaterial is subject to a remote uniform and constant tensile loading, the normal stress along the crack line (including tip) is almost time independent. In contrast, the relative crack surface displacements and crack energy release rate do change with time, and are very much dependent on the creep compliance of the viscoelastic material. The tendencies of the crack advancing along the interface, and kinking out of the interface, are estimated and discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.