MECHANICS OF ADHESION - Nanoindentation with Biological Applications - page 83

Figure 4-5. The variations in the full potential, force, and stiffness (solid lines) with tip
position for combined logarithmic and harmonic potentials (dotted lines) for an imposed
tip position smaller than the critical tip-surface separation, such that no equilibrium tip
position is possible. The values are normalized using the characteristic values ( Eq. 4-9 ).