Adhesive contact between an elliptical rigid flat-ended punch and an elastic half space

The adhesive contact between an elliptical rigid flat-ended punch and an elastic half space was analysed in this study. Non-self-similar growth in the contact area was obtained. The separation was found to initiate at the edges of the major axis, which would lead the elliptical contact to a circular contact. The pull-off force for the initiation of separation increases from the slim elliptical contact to the circular contact and is proportional to the square root of the interfacial energy and shear modulus of the elastic material. A relation between the pull-off force and the corresponding punch displacement was obtained, which is independent of the elastic properties of elastic materials.