Simulation of ballistic impact tests under various conditions for a nickel-base superalloy

Smooth and round notched tensile specimens with three different notch radii as well as single-edge bending specimens were tested in two high strain-rate testing machines at various strain-rates and temperatures. The experimental data were used to identify the parameters of the Johnson-Cook deformation and failure model using the evolution strategy and LS-DYNA calculations respectively. Ballistic tests with both, the projectiles and target plates made from the same material were performed at different projectile velocities and with two different projectile tip shapes (blunt and conical) as well as with three different target thicknesses, target angles and at two different target temperatures. The calibrated Johnson-Cook models were successfully applied in LS-DYNA in an uncoupled manner to simulate these tests. In all FE simulations the integrative nonlocal Pijaudier-Cabot & Bazant method was applied for reducing the mesh dependency of the failure time