Design of Ballistics Armor Using Additive Manufacturing of Kevlar Composites

This project evaluates the effectiveness of various geometries created using advanced additive manufacturing (AM) of Kevlar fiber, chopped carbon fiber-reinforced filament for ballistic protection applications. This study expands on sandwich panel designs with woven Kevlar face sheets and investigates an optimal fiber reinforced filament core structure design. A unit cell workflow was developed in nTop to take advantage of its custom cell modeling and FEA capabilities. Unit cell types were simulated and tested from the hexagonal honeycomb, gyroid TPMS, and re-entrant auxetic cell families. Core structure thickness and cell size were additive manufacturing parameters that were varied to assess the impact absorption. Moreover, the additively manufactured cell structures were encapsulated with a damping material, particularly silica. To determine the best kind of silica for ballistic applications, 3 kinds of silica with varying tensile strengths were molded into a shape similar to the cores. The samples were then tensile tested using an INSTRON universal testing machine to determine which offered the best balance between strength and ductility. The experimental approach began by determining the material characteristics for test coupons for both continuous fiber and chopped fiber in 0- and 90-degree filament orientations.