In this paper, an equation for calculating hardness under dynamic conditions is derived utilizing dislocation density definitions based on conservation of energy principle. In addition, finite element analysis of dynamic impact problems are carried out and compared to analytical solution to predict hardness behavior versus impact velocity for different indenter shapes. Indenter shapes considered in the research were spherical, cubical, and conical. Finite element results show reasonably good match with the analytical solution at low ranges of impact velocities, but diverge at higher values, which should be considered through different behaviors of deformation at such velocities.
