Energy absorption of three-dimensional angle-interlock woven composite under ballistic penetration based on a multi-scale finite element model

This paper reports the ballistic energy absorption of three-dimensional angle-interlock composite (3DAWC) based on a ballistic experiment and a theoretical model with high strain rate constitutive equation of fiber tows. The 3DAWC panels were penetrated under a hemispherical–cylindrical steel projectile, while time testers recorded the initial velocities and residual velocities of projectile in this process. The damage modes of 3DAWC are observed and analyzed from the view of penetrated damage morphologies and experimental velocity data. In order to demonstrate the energy absorption mechanism with more accuracy, a multi-scale finite element model of 3DAWC under ballistic penetration is specially designed and established to calculate this ballistic event. The constitutive relationship of the Twaron® filament yarn in microstructural model is derived from the springs and dashpots model and compiled into user-defined material subroutine in commercial-available finite element software package LS-DYNA, which can introduce strain rate sensitivity of fiber bundles to ballistic energy absorption process. A comparison of theoretical and experimental results shows a good agreement indicating an accurate validity of the multi-scale finite element model of 3DAWC. Moreover, this model can deeply reveal the ballistic energy absorption mechanism of 3DAWC which will help to evaluate the structural tolerance of ballistic protection composite material.