Determination of Johnson–Cook Material Parameters for Armour Plate Using DIC and FEM

Understanding of material behavior of armour steel under large deformations and high strains during loading is very crucial in designing steel structures for various applications. Johnson–Cook flow stress and Johnson–Cook failure models were adopted for modeling and predicting the material flow behavior of armour plate. The material parameters of Johnson–Cook flow stress have been determined experimentally from tests performed at different strain rates (10−4–1550 s−1) and temperatures (25–600 °C). The damage parameters of Johnson–Cook failure model were determined through experiments on flat tensile specimens in combination with finite element simulation. Using these materials parameters, finite element simulations were performed on notch specimens of different radii between 2 mm and 20 mm loaded under tension. Load-strain curves were in good agreement with the experimentally obtained data. Triaxiality obtained from simulation were matched against the reported values from the literature.