Ballistic impact response for two-step braided three-dimensional textile composites

We are concerned with the ballistic impact response of three-dimensional two-step braided textile composites struck by a 36.1-g hemispherical tip-ended rigid cylindrical projectile. A series of quasistatic punch tests using a hemispherical indentor have been conducted to investigate the progressive damage modes of the target and to obtain the punch load-displacement relationship. In addition, a pneumatic launcher is used to propel the projectile with incident velocities ranging from 70 to 170 m/s. The ballistic limit is experimentally determined to be near 74.1 m/s. Commercially available finite element code (MARC) is incorporated with the constitutive relationship for three-dimensional two-step braided composites and the proposed static penetration model to simulate the dynamic impact response. An energy consideration is applied to predict the projectile's residual (or terminal) velocity. Numerical simulated result based on the static elastic properties of the target tends to overestimate the projectile terminal velocity. When the target's elastic moduli used in simulation are increased by 1.5 times the static values, good agreement is found between the simulated terminal velocities and test results for projectile incident velocities ranging from 70 to 180 m/s.