A Microstructure Analytical Model Of 3-d Woven Fabric For Ballistic Penetration Calculation

Yarns in 3-D angle interlock woven fabric (3DAWF) are not only laid in warp or weft directions, some yarns are also interlaced with constant angle in thickness direction. The inter-laminar strength of 3DAWF is strengthened significantly owing to the existence of the angle interlacing yams. Meanwhile, its deformability and energy absorbency are also improved by the crimpness of one system yarns.The 3DAWFs can be designed into many different structures, which have different energy absorption abilities. In this paper, one kind structure of 3DAWF was chosen for analyzing the impact deformation and energy absorption.An analysis model was established which based on the micro-structure of 3DAWF to explore its deformation and energy absorption mechanism under ballistic penetration by a rigid projectile. First, a simplified geometrical model of the 3DAWF structure was built. Then the deformation and failure of the fabric target was analyzed by energy method. The energies absorbed by warp and weft yams with different crimp coefficients in transverse and longitudinal wave regions were calculated. The strain rate effect on mechanical properties of the warp and weft yarns was employed in modeling to estimate the penetration time. And also, the strain rate versus strike velocity of projectile curve was fitted. Theoretical residual velocity versus strike velocity curve were obtained and compared with that in experimental. The energy absorption distribution of the 3DAWF under ballistic impact was analyzed with the verified model. And meanwhile, the energy absorption mechanism of the fabric target was revealed. It was found that the strain energy was the major way of energy absorption. It was also found that yarn crimp coefficient and weave density were key factors influencing fabric ballistic behavior.The research method and the calculation results developed in this paper will provide a basis for designing the soft fabric armor, and can be further applied to predict and evaluate the ballistic performance of other 3DAWFs or 3-D woven fabrics.