Multiaxial Inverse Stress Analysis for Indentation Creep

Abstract

This paper presents an extracting method of creep exponent and coefficient in Norton’s law from an indentation creep test analytically, assisted by a finite element analysis. Previous studies extracted only the creep exponent empirically with no theoretical verification. No extracting method on the creep coefficient has been proposed from an indentation creep test. By analyzing multiaxial stress states under a ball indenter in combination of a creep constitutive equation, an analytical method to derive the creep coefficient is developed. The method is verified to have a satisfactorily accuracy to determine the two material constants in Norton’s law by finite element analyses and in experiments.