Ballistic penetration of conically cylindrical steel projectile into plain-woven fabric target - A finite element simulation

This paper gives a finite element model to simulate the entire process of multilayered fabric target perforated by conically cylindrical steel projectile on the basis of the description of the actual structure of fabric considering crimps of warp and weft yarns. Commercially available finite element code Ls-Dyna is incorporated with the Weibull constitutive equations of filament yarns at high strain rate to simulate the ballistic impact response. The projectile and yarns in the fabric are meshed with a eight-node hexahedron element (Solid 164 in Ls-Dyna). From the comparisons of the residual velocities of the projectile, and deformation and damages of the fabric target after ballistic perforation between the experimental results and theoretical ones, it is proven that at the yarn-structural hierarchy, the finite element method with explicit algorithm and code Ls-Dyna could precisely simulate the ballistic impact between the steel projectile and the fabric target. It is also found from calculations that only when the mechanical properties and constitutive equations at a high strain rate are adopted in the finite element model, can the precision of simulation be improved. An interesting and nonintuitive result is that the existence of fabric interspaces between the interweaved yarns could not decrease the kinetic energy absorptions of the fabric target perforated by the projectile under the ballistic impact. The original ideas of this paper are the considerations of the actual structure of multilayered fabric target and the constitutive equations of yarns at a high strain rate in the finite element model. Compared with other papers in this field, the FEM model proposed in this paper can simulate the interaction between the projectile and the multilayered fabric target more precisely in fabric target deformation, kinetic energy absorption, and strain wave distribution. This model can also be extended to other fabric structures and materials under the ballistic impact.