Finite deformation effects in homogeneous and interfacial fracture

This paper summarizes recent results of asymptotic, numerical and experimental investigations of some nonlinear effects on the mechanics of fracture in homogeneous and bimaterial sheets of a particular class of hyperelastic incompressible materials. The problem is analysed within the framework of the finite strain theory of plane stress. Material induced nonlinearities are included through the use of the generalized neo-Hookean model which is characterized by three parameters which determine the small strain, "yielding" and "hardening" responses of the component(s). The structure of the near-tip stress and deformation fields is described and compared to a full-field finite element investigation. The consequences of the local results on the propagation behavior of a crack under general in-plane loading are outlined in the special case of a homogeneous sheet. The analytical results are corroborated by experimental observations obtained on natural rubber sheets.