The strain energy density approach applied to bonded joints

Adhesively bonded joints can be treated as bi-materials characterized by a stress singularity promoted by both geometrical and constitutive discontinuities, very close to the point where the interface between two elastic solids intersects a traction-free edge. Different approaches have been proposed to predict their both static and fatigue strength. Most of them are based on the stress distribution at the interface between the adherent and the adhesive. More recently, energy density-based criteria have been developed to predict the static and fatigue strength of mono-material notched components, like welded joints. The most promising one is the strain energy density approach in which it is assumed that failure occurs when the strain energy density, averaged over a control volume of critical radius Rc surrounding the singularity point, will reach a critical value. Advantages are different. Among the others, the strain energy density doesn't depend on the singularity order and doesn't require a fine mesh. This contribution is aimed at applying the strain energy density criterion to bonded joints.