Ballistic performance and energy absorption characteristics of thin aluminium plates

• Ballistic performance and energy dissipation in thin aluminium targets was studied.
• Target to projectile diameter ratio was varied, 3.6–40, by varying target diameter.
• Ballistic limit increased with increase in target to projectile diameter ratio (D/d).
• Against ogive nosed projectile maximum energy dissipated in tangential stretching.
• Against blunt projectile, circumferential and radial stretching was more prominent.

The paper presents an experimental and finite element investigation to explore the influence of target to projectile diameter ratio (D/d) on the ballistic performance and failure mechanism of thin aluminium plates. 1100-H12 aluminium target plates of 1 mm thickness were impacted by 19 mm diameter ogive and blunt nosed projectiles. The D/d ratio was varied by varying the span diameter of the target keeping the projectile diameter constant, 19 mm. The finite element simulations were carried out at D/d ratios 3.6, 5, 7.9, 10, 15, 20, 25, 30, 35 and 40. The validation of the simulation results was carried out by performing experiments at D/d ratio 3.6, 5, 7.9, 10 and 15.The total work done in plastic deformation of the target was disintegrated into circumferential, radial, axial and tangential stretching. An initial increment in D/d ratio from 3.6 to 10 has been found to have prominent effect on the ballistic limit particularly against blunt nosed projectile. Subsequent increase in the D/d ratio however, could not influence the ballistic resistance significantly. The energy absorption inplastic deformation was found maximum for D/d ratio 10. The maximum energy dissipation occurred in circumferential stretching against bunt and in tangential stretching against ogive nosed projectile. The minimum energy dissipated in axial stretching against both the projectile.