Abstract
Analytical model is presented herein to predict the diameter of crater in semi-infinite metallic targets struck by a long rod penetrator. Based on the observation that two mechanisms such as mushrooming and cavitation are involved in cavity expansion by a long rod penetrator, the model is constructed by using the laws of conservation of mass, momentum, energy, together with the u-v relationship of the newly suggested 1D theory of long rod penetration (see Lan and Wen, Sci China Tech Sci, 2010, 53(5): 1364–1373). It is demonstrated that the model predictions are in good agreement with available experimental data and numerical simulations obtained for the combinations of penetrator and target made of different materials.
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Abbreviations
- ρ :
-
density
- ρ p :
-
density of penetrator
- ρ t :
-
density of target
- v :
-
velocity of the undeformed rear of a long rod penetrator
- u :
-
penetration velocity
- Y p :
-
penetrator strength
- R t :
-
target resistance
- S :
-
static target resistance
- C :
-
constant of the dynamic resistive pressure
- U F0 :
-
critical penetration velocity, defined as U F0 = (HEL t/ρ t)1/2
- δ :
-
a function of u, defined by eq. (17)
- n :
-
constant, defined in eq. (17)
- HEL :
-
Hugoniot Elastic Limit
- HEL t :
-
HEL of target material
- r :
-
initial radius of the cross section of a long rod penetrator
- R m :
-
radius of the penetrator mushroom
- A p :
-
initial area of the cross section of a long rod penetrator
- A e :
-
cross-sectional area of the debris
- V e :
-
ejecting velocity of the debris
- ϕ :
-
Ap/Ae
- θ :
-
tangle between arbitrary radius of the semispherical surface and penetration centerline
- p :
-
pressure on the surface of a spherical nose
- u n :
-
normal component of penetration velocity on the surface of the penetrator nose, viz. u n = ucos θ
- F tN :
-
integration of p over 0 ⩽ θ ⩽ π/2
- R crater :
-
total crater radius
- I :
-
F tN /(πr2)
- d m :
-
mushroom diameter, viz. d m = 2R m
- d t :
-
total crater diameter, viz. d t = 2R c
- V 0 :
-
impact velocity
- V C :
-
critical velocity corresponding to u = U F0
- A 0 :
-
initial cross-sectional area of a long rod penetrator
- A c :
-
total crater area
- E 1 :
-
elastic modulus
- E 2 :
-
plastic modulus in a bilinear material model
- Y 0 :
-
yield stress or proof stress in a true tress-strain curve
- Y :
-
yield stress in a bilinear material model
- V :
-
poisson ratio
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Wen, H., He, Y. & Lan, B. Analytical model for cratering of semi-infinite metallic targets by long rod penetrators. Sci. China Technol. Sci. 53, 3189–3196 (2010). https://doi.org/10.1007/s11431-010-4101-6
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DOI: https://doi.org/10.1007/s11431-010-4101-6