Test MethodCharacterization of viscoelastic-plastic properties of solid polymers by instrumented indentation

This paper presents formulae for visco-elastic-plastic response to indentation for various indenter shapes and times of loading, and describes a procedure for obtaining parameters of creep compliance function from monotonic load. The application is illustrated on PMMA, whose properties are measured under constant load and in a load-unload test. A discussion follows on the influence of indenter shape, various forms of creep compliance function and the relation between the test duration and the model. Also, other information obtainable from nanoindentation tests is mentioned: apparent modulus, hardness and components of creep compliance function.