Hardness tests used to establish constitutive models

In this report a study of the hardness of different materials are performed theoretically and experimentally. The objective was to study whether the hardness test could be used to establish constitutive material models. We apply the famous cavity theory for rigid penetration for the hardness test, and expand the theory to include compressibility and strain hardening. We found discrepancies between the results from cavity theory and the experimental results. Contrary to the theory, the hardness is dependent on the form of the penetrator. Also the cavity theory overestimates the hardness with approximately 20% for the steel specimen and the Wolfram Carbide specimen. In general we show that material data from the hardness test can be used as an important input to construction of constitutive material models.