Projectile penetration into concrete with an inline hole
This study is an experimental and analytical investigation of projectile penetration into concrete with an inline hole. An experimentally verified equation of projectile penetration into concrete with an inline hole is presented. Velocity varied from 91 to 401 m/s, and hole/projectile diameter ratio d/D varied from 0 to 0.969. Projectile diameters of 2.20 and 8.86 were used. The standard deviation of the penetration was 9% when the penetration as derived from the equation was compared to the experimental penetration. Experiments showed that projectile penetration depth was dependent on velocity to the 1.5 power, which was the same as a previously published relationship for projectile penetration into concrete without a hole. A finite-element program was used to gain an understanding of the penetration mechanics for the experiments with a projectile diameter of 8.86 cm. Finite-element-calculated penetration for the case without a hole (d/D = O) was 23% low, because strain softening (decrease in strength at high strain) and concrete crater ejecta were not modeled. Finite-element-calculated penetration for a projectile with a velocity of 355 m/s was 22% high, possibly due to strain-rate effects. The relative importance on projectile penetration of concrete dynamic/static strength, equation of state, bulk unloading modulus, coefficient of friction, and finite-element mesh resolution change with the d/D ratio. Projectile penetration for the case of a large hole (d/D = 0.969) was particularly sensitive to the coefficient of friction, leading to an estimate of 0.024 +- 0.012 for the high-velocity concrete coefficient of friction. Projectile penetration into a geologic material with a large hole (d/D greater than or equal to 0.97 and < 1.0) and accompanying finite-element analysis of the data can lend itself to the approximation of high-velocity friction coefficients for geologic materials. 29 refs., 10 figs., 2 tabs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6414188
- Report Number(s):
- UCRL-53786; ON: DE87010852
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
450100* -- Military Technology
Weaponry
& National Defense-- Chemical Explosions & Explosives
BUILDING MATERIALS
CONCRETES
DATA
EQUATIONS
EQUATIONS OF STATE
EXPERIMENTAL DATA
FINITE ELEMENT METHOD
FRICTION
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
NUMERICAL DATA
NUMERICAL SOLUTION
PENETRATION DEPTH
PROJECTILES
VELOCITY