Ballistic impact damage of biaxial multilayer knitted composite

This paper reports ballistic impact properties of a biaxial multilayer warp knitted basalt/vinyl ester composite from experimental and finite element analysis approach. In experimental, the ballistic perforation tests were conducted to obtain the energy absorption and impact damage of the composite plate penetrated under cylindro-ogive steel projectile (Type 56 in China Military Standard). In finite element analysis approach, a unit-cell model of the biaxial multilayer warp knitted composite has been developed based on the microstructure of the biaxial multilayer warp knitted composite. Critical damage area failure criterion was combined in the unit-cell model to determine the composite damage. A user-defined subroutine vectorized user defined material law was written to define the composite constitutive equation and failure criterion under impact. Incorporated with commercial finite element software package ABAQUS/Explicit, impact damage and energy absorption of the composite plate were calculated. Numerical predictions are compared with the experimental observations in terms of impact damage and energy absorption. We hope such an effort could be extended to the ballistic protection design of knitted composite.