Numerical investigation on the hybridization effect in inter-ply S2-glass and aramid woven composites subjected to ballistic impacts

Hybrid composites may be used to improve the ballistic properties of structures. These composites may be produced by enhanced manufacturing process that allow obtaining desired protection level and reducing costs. However, large variability in the material selection and architecture makes the correct choice a complex task that, in the past, has been mainly faced by experimental technique. To reduce experimental efforts, the use of predictive modelling approaches is a current attractive possibility. This work focuses on numerical simulations of the ballistic impact on different combinations of inter-ply hybrid composites of woven Kevlar and S2-glass. The numerical analyses are carried out employing LS-Dyna MAT_162, which accounts for progressive inter- and intra-laminar failure modes. Some materials mechanical properties are obtained through tests and the parameters accounting for strain rate and softening are calibrated. This is crucial to obtain an accurate model, avoiding to address the calibration task in a pure numerical and parametric way. The effect of the stacking sequence and target thickness on the ballistic curves, the ballistic limit velocity and the absorbed energy by the target, are discussed. The numerical models show high accuracy in predicting the residual velocity, ballistic limit and damage features.