Investigation of projectile nose shape and impact obliquity on the ballistic performance of carbon reinforced aluminum laminates

초록

In the present study, the ballistic performance of carbon reinforced aluminum laminates (CARALL) under normal and oblique impact with flat nose (CP) and truncated cone nose (TP) projectiles is investigated experimentally and numerically. Ballistic tests are carried out on normal impact for CP projectiles using a one-stage gas gun at velocities up to 191.5 m/s. The ballistic behavior of the TP projectile is studied using the finite element (FE) model implemented in LS-DYNA hydrocode. The simulations are performed for oblique impact in the range of 20 degrees-80 degrees. The ballistic limit is found to be 73.7 m/s for CP and 75.0 m/s for TP projectiles with a difference of 1.7% suggesting that the perforation threshold of CARALL laminates is weakly affected by the projectile nose geometry. At impact angles less than 40 degrees, the observed failure types are plugging, petalling and interlaminar delamination, a mixed bending-sliding response between 60 degrees and 70 degrees and a surface controlled ricochet behavior at angles greater than 70 degrees. The results show that CARALL laminates can be considered to have shape-independent ballistic limits and to maintain their impact resistance under a wide range of oblique loading conditions.

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