Adhesive contact between flat punches with finite edge radius and an elastic half-space

In this paper, the adhesive contact of elastic solids with flat surfaces with an edge radius is studied within the frame-work of Johnson-Kendall-Roberts theory. Solutions are obtained for the stresses at the contacting surfaces and for the relative displacement of the two bodies due to adhesion and applied load. Results are given for flat-ended punches with rounded edges of small radius to nearly spherical objects with small flat areas (truncated spheres) on their surfaces. The classical Johnson-Kendall-Roberts-model for adhesion and contact between spherical surfaces arises as a limiting case of the results. The pull-off force between the adhering bodies is deduced for the flat-surfaced geometries studied. For small flats, the numerical solutions are similar to the classical Johnson-Kendall-Roberts solution for a sphere.