Possibility of Shear Fracture in Low-Velocity Impact of Al-6061 Projectiles on Al-6061Plates

Experiments on low-velocity impacts of hollow cylindrical Al-6061 projectiles on thin Al-6061 plates are modelled using smooth particle hydrodynamics technique using Johnson-Cook and Bao-Wierzbicki damage models. At 65 m/s, the projectile dents the target plate while at 85 m/s, the target is perforated. The dent profile is adequately represented in the simulations except that the central dent is underestimated by ∼10%. The numerical procedure allows for a well-defined demarcation of shear and tensile damage by the degree of triaxiality and the simulations at 85 m/s show that the tensile damage exists over a greater spread in the target plate and has a magnitude an order greater than the shear damage. Hence, the tensile damage and thus JC damage model would adequately describe the low-velocity impact of Al-6061 projectiles on thin Al-6061 plates.