  Application of the principle of energy balance to a rigid indenter in contact
with elastic layer on a flat rigid substrate provides a very simple derivation
of the detachment criterion which earlier has been obtained by much more
complicated asymptotic analysis. This criterion allows calculating the adhesive
strength of arbitrary contact of a flat-ended indenter, which occurs to be
proportional to the area of the face of the indenter and does not depend on its
shape. Similarly, the adhesive contact problem can be easily solved in the case
of arbitrary three-dimensional shape.
