DURABILITY-AFTER-IMPACT OF ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE ARMOR COMPOSITES

摘要

Ultra-high molecular weight polyethylene (UHMWPE) composite laminates exhibit incrediblernballistic efficiency, and are thus desirable for use in many protection applications. However, arnconcern for UHMWPE armor is the durability of the composite laminate throughout its lifecycle.rnIn this study, single curvature UHMWPE composite laminates (rc = 200 mm) were processed andrnsubjected to drop testing to simulate in-field damage of helmets in theater being droppedrnrepeatedly or damaged through low-velocity blunt impact events (such as a fall). Two impactrnloadings (21.9 and 57.8 J) and three life cycles were explored (1, 2.5, and 5 years). Drop testedrnpanels were subsequently assessed ballistically using 9 mm 124 gr. full metal jacket (FMJ)rnprojectiles. In these ballistic experiments, the UHMWPE panels demonstrated a reduction inrnlocalized dynamic ballistic deformation due to both increasing load and longer lifecycle.rnNumerical modeling using LS-DYNA validated the behavior observed in the experimental testingrnof the panels, and revealed the reduction in deformation to be characteristic of the geometry of thernindentation imbued to the structure of the UHMWPE composite during the drop testing.