The responses of viscoelastic solids indented by flat-ended cylindrical and spherical tip indenters are analyzed in this paper. The viscoelastic solid is a semi-infinite medium described by a standard three-element model. The theoretical relaxation and creep solutions are derived for a viscoelastic half-space using the method of functional equations. These solutions can apply to the responses of compressible as well as incompressible coatings to flat-ended cylindrical punch and spherical tip indentation. They establish a fundamental basis for probing mechanical properties of polymeric coatings with micro- and nanoindentation tests. To obtain the strain and stress distributions, an explicit finite difference method is employed to solve a viscoelastic indentation problem. The experimental creep and relaxation tests are conducted on both bulk polystyrene and polyurethane coatings. The viscoelastic properties are derived by fitting the theoretical solutions with the experimental data measured.
|Original language||English (US)|
|Number of pages||6|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - Dec 1 1998|
|Event||Proceedings of the 1998 MRS Spring Symposium - San Francisco, CA, USA|
Duration: Apr 13 1998 → Apr 15 1998