Numerical Analysis of Effect of STF with Frictional Hypothesis on Impact of Ballistic Projectile to Fabric Made of Kevlar 29 Fibers

Investigation of the effect of the STF on increasing of frictional energy on Kevlar fibers as one of the main factors of decreasing permeability in ballistic impacts is very important. In this study, for understanding the effect of STF on decreasing the permeability of fibers by increasing the frictional energy between fibers and projectile was modeled by ANSYS15 software. The projectile was impacted to the target with velocity of 350m/s. In both models the projectile penetrated and crossed the target. In modeling with Kevlar 29 fibers, the output velocity of projectile was about 341.88m/s and in second modeling the output velocity was 306.43m/s. This model was compared with previous experimental model; ballistic limit of Kevlar fiber without STF is also compared. The results demonstrated the effect of STF on decreasing the permeability of Kevlar fibers because of increasing the friction coefficient. According to the results, increasing the friction coefficient of more than 3 did not have significant effect on decreasing permeability.