Effects of three-dimensional geometry on penetration and perforation resistance

This thesis determined the penetration and perforation thresholds of laminated, stitched, and two- and three-dimensionally woven composite plates subjected to transverse impact. All composite plates were made from glass/epoxy prepreg tape so direct comparisons could be made about the effects of through thickness reinforcement on penetration and perforation thresholds. The effects of fiber angle were also studied. The laminated plates were made with various stacking sequences and had no additional through thickness reinforcement. The stitched plates were reinforced through the thickness with one-millimeter wide strips of prepreg. The two- and three-dimensional plates were hand woven using 12.7 mm wide strips of prepreg. The three-dimensional weaving technique was innovative in that it incorporated new fabric geometry to reinforce the plates through the thickness. A drop weight tester with an instrumented tup was used to impact the plates. The impact test data was used to determine the penetration and perforation thresholds. The three-dimensional woven plates had larger penetration and perforation thresholds than the laminated and two-dimensional plates as well as reduced delamination areas. The stitched plates had the largest penetration and perforation thresholds. Through thickness reinforcement increased penetration and perforation thresholds. The fiber angles of the laminated and three-dimensional plates also influenced their penetration and perforation thresholds.