Article

Perforation of 12mm thick steel plates by 20mm diameter projectiles with flat, hemispherical and conical noses: Part I: Experimental study

Structural Impact Laboratory (SIMLab), Department of Structural Engineering, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
International Journal of Impact Engineering DOI:10.1016/S0734-743X(01)00034-3

ABSTRACT Projectiles with three different nose shapes (blunt, hemispherical and conical) have been used in gas gun experiments to penetrate 12 mm thick Weldox 460 E steel plates. Based on the experimental results, the residual velocity curves of the target material were constructed and compared. It was found that the nose shape of the projectile significantly affected both the energy absorption mechanism and the failure mode of the target during penetration. The ballistic limit velocities were about equal and close to 300 m/s for hemispherical and conical projectiles, while it was considerably lower for blunt projectiles. Blunt projectiles caused failure by plugging, which is dominated by shear banding, while hemispherical and conical projectiles penetrated the target mainly by pushing the material in front of the projectile aside. Also, the residual velocity curves were influenced by nose shape, partly due to the differences in projectile deformation at impact. The experimental study, given in this part of the paper forms the basis for explicit finite element analysis using the commercial code LS-DYNA presented in Part II of the paper.

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Keywords

Blunt projectiles
 
commercial code LS-DYNA
 
conical projectiles
 
different nose shapes
 
energy absorption mechanism
 
equal
 
experimental results
 
experimental study
 
explicit finite element analysis
 
failure mode
 
gas gun experiments
 
hemispherical
 
nose shape
 
penetration
 
projectile deformation
 
projectiles
 
residual velocity curves
 
shear banding
 

T. Børvik