Finite-element modeling of the ballistic impact of fabric armor

This paper investigates the finite-element simulation of ballistic impact on Twaron® fabric through proposing a material model, which incorporates viscoelasticity and a strain-rate-sensitive failure criterion. A non-linear, explicit, three-dimensional finite-element code DYNA3D is used to simulate the response of fabric under high-speed projectile impact. The fabric is modeled using membrane elements. Suitable material properties to account for its viscoelastic nature are obtained through mathematical manipulation of the three-element spring-dashpot model and by use of available experimental data. The ballistic limit, residual velocity, energy absorption and transverse deflection profiles of the fabric are predicted and compared with those from experiment. The limitations of the proposed model, in terms of representing fabric behavior such as frictional effects between yarns and unraveling and fraying of yarns are recognized. Nevertheless, the model provides a fairly accurate representation of the strain-rate-dependent behavior of fabric.