Review Article
Indentation Depth Dependent Mechanical Behavior in Polymers
Table 1
Projected contact area, surface area, angles, geometric constants, and geometry correction factors for common indenter geometries [55] where is the contact depth (shown in Figure 1(b)), is the indentation depth under applied force (see Figure 1(a)), is the radius of spherical tip, is the semiangle of indenter tip (for pyramidal tips is the face angle with the central axis of the tip [55]), is the half angle defining an equivalent cone, is the geometric constant (for the pyramidal tips is theoretically 0.72; however, a value of 0.75 has been experimentally found to better represent experimental data [55]), and is the geometry correction factor used for the determination of elastic modulus [53]. Note that and given in Table 1 for Berkovich, Vicker, Knoop, cube corner, and cone indenters are, respectively, the projected and surface areas of a perfectly sharp indenter without imperfection/bluntness (see, e.g., [53, 55], for the projected contact area of a blunt indenter).
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