A Numerical Study on Prediction of BFS in Composite Structures under Ballistic Impact

Back Face Signature (BFS: maximum permanent displacement at the back face of the plate) is one of the important performance factors criteria laid down for the standardization of body armors. In the current work, BFS of a composite plate under ballistic impact are determined for Kevlar 29 and 129 composite panels. Numerical studies using explicit time domain approach has been carried out to determine the ballistic response of the target plate through direct impacts of two types of rigid projectiles. Tie–break interface is used to model inter-ply delamination and contact. Effects of various parameters such as material stiffness, impactor geometry are determined. The BFS is estimated for various cases considering different impact velocities (140m/s-500m/s). Validation study for the present FE model explained above and subsequent results of dynamic analysis are verified through the existing results reported in the literature.