Crack tunneling and plane-strain delamination in layered solids

Steady-state tunneling and plane-strain delamination of an H-shape crack are examined for elastic, isotropic multi-layers. Both tunneling and delamination are analysed by employing linear elastic fracture mechanics within a 2D finite element framework. Failure maps are produced to reveal the sensitivity of cracking path to the relative toughness of layer and interface, and to the stiffness mismatch of layers. Closed-form expressions are derived for the critical stress level for steady-state plane-strain delamination. By means of a comparison with experimental results taken from the literature, it is demonstrated that these expressions serve as useful design criteria for elastic multilayers. © 2004 Kluwer Academic Publishers.