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Successive impact of segmented rods at high-velocity

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Abstract

The penetration capabilities of segmented rods consisting of multiple, small aspect ratio segments, (l/8<L/D < 1) are examined. Our investigation consisted of a series of axisymmetric numerical simulations for constant mass, diameter, and collapsed length. The calculations are limited to tungsten alloy in the form of segmented rods impacting rolled homogeneous armor steel (RHA) at 2.6 km/s successively with infinite spacing. The results of our numerical calculations show that the degradation of penetration performance of successive segments is indeed more pronounced for segments of smaller aspect ratios even at an impact velocity of 2. 6 km/s. There is a continual degradation of performance forL/D < 1 segments with the amount of degradation increasing as the aspect ratio decreases. The degradation in penetration is attributed to the material remaining in the cavity. This is verified from another set of simulations (the projectile residue was removed before the impact of the successive segments) which shows almost no degradation. There is a shift in the optimal segment size toward increasing segment aspect ratios when multiple segments are considered as compared to when only single segment performance is considered.

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Abbreviations

D :

Segment diameter

D c :

Cavity diameter

G:

Shear modulus

KE :

Impact kinetic energy

L :

Projectile length

L t :

Collapsed length

P :

Penetration depth

P t :

Accumulated penetration depth

V :

Impact velocity

V c :

Cavity volume

Y:

Yield strength

ɛp :

Equivalent plastic strain

ɛ* :

Dimensionless plastic strain rate

ρ p :

Density of projectile

ρ t :

Density of target

σ :

Von Mises effective flow stress

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Correspondence to Minhyung Lee or Michael J. Normandia.

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Lee, M., Normandia, M.J. Successive impact of segmented rods at high-velocity. KSME International Journal 13, 312–320 (1999). https://doi.org/10.1007/BF02939319

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Key Words

  • Segmented Rods
  • Impact
  • High Velocity
  • Penetration
  • Degradation