A Refined Quasi-microstructure Model for Finite Element Analysis of Three-dimensional Braided Composites Under Ballistic Penetration.

The nondelamination characteristics of three-dimensional (3-D) braided composites under ballistic impact makes them possess considerable potential in ballistic protection applications. However, there are only a few references concerning the calculation of ballistic properties of these composites, and all are based on the continuum assumption of composite materials. In this paper, a refined quasi-microstructure model constructed with crossed inclined laminae of the same braided yarn with the same diameter and fiber volume fraction as in the 3-D braided composite at the actual microstructure level is established to analyze the ballistic penetration of 3-D braided composites target by a rigid projectile. The calculated results of the finite element analysis (FEA) are conservative to estimate the penetration resistance of the composite. From the acceleration-time history of the projectile and the damage morphology of the 3-D braided composite in FEA, it is indicated that the refined quasi-microstructure model can approximately simulate the real ballistic impact damage of these composites. The original ideas of this refined quasi-microstructure model are the scheme of decomposing the 3-D braided composite with the inclined lamina at its actual microstructure level and the adoption of constitutive equations of the reinforced fibers at a high strain rate. This model can also be extended to calculate the ballistic penetration of other 3-D textile preform-reinforced composites by rigid projectiles. [ABSTRACT FROM AUTHOR]