The Effect of Out-of-Plane Fiber Waviness on the Ballistic Performance of Ultra High Molecular Weight Polyethylene(UHMWPE) Laminates

Abstract

In this study, the effect of out-of-plane fiber waviness on ballistic performance of thin compliant laminates was investigated. Waviness varying from 2.46% to 32.27% was artificially induced into thin DSM Dyneema® HB50 laminates. Analogous to crimp in woven textiles, waviness is defined as the fraction of total arc length divided by the wavelength of the crimping. Several amplitudes and wavelengths of undulations were investigated. The ballistic limit of each sample against a 17 grain Fragment Simulating Projectile (FSP) was determined and high speed videography was used to track the longitudinal and transverse wave positions as a function of time. It was found that outof- plane fiber waviness had a significant deleterious effect on both the transverse wave velocity and the maximum energy absorption of the laminates before failure. It was found that small, high frequency undulations were more deleterious than large, low frequency undulations due to the increased number of wave reflections.