On the Simulation of Microhardness at Large Strains Using a Gradient Theory of Plasticity
Indentations tests, e.g. the Brinell and Vickers tests, are frequently exploited to eval-uate
the hardness of metals, which reflects the elastic as well as the plastic properties. It is a
well-known fact that the hardness shows significant size-effect when the diameter of the inden-ter
is of the order of one micron in the context of engineering metals. In this contribution we
employ a recently developed gradient theory of macroscopic plasticity in order to evaluate such
microhardness. The proposed gradient theory is thermodynamically consistent and is valid for
large inelastic strains (as well as large elastic strains; however, the elastic strain remains small
in the present application), cf. (Svedberg, 2000). Finite element simulations demonstrate the
size-effect on the hardness for different head-shapes of the indenter.
Thomas SVEDBERG, Kenneth RUNESSON
Reçu le 10 septembre 2001.
Accepté le 22 octobre 2001.
Microhardness, gradient plasticity, large strains.