Post failure analysis of 0 degrees /90 degrees ultra high molecular weight polyethylene composite after ballistic testing

Abstract

The ballistic performance of a 0 degrees /90 degrees ultra high molecular weight polyethylene (UHMWPE) composite was investigated. Two areal densities were considered: one for fragmentation protection and one for high velocity bullet protection. The role of microscopy in the post-failure analysis of the UHMWPE was explored. Stereo, optical and environmental scanning electron microscopy were utilized and attempts were made to correlate the results obtained with other characterization techniques available. These included high speed photography, visual inspection and ultrasonic inspection. Visual inspection revealed the gross effects of ballistic testing. These primarily included deformation and delamination of the composite plate. The result obtained corresponded with the predicted impact event and, for high velocity bullet impact, corresponded well to the images obtained using high speed photography. Optical, stereo and electron microscopy allowed for fibre and matrix characterization. Fibre displacement and pull-out were also observed on impact and exit faces.