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Experimental Investigation of Multiaxial Loading Behavior of UHMWPE Yarns Using a Fragment Simulating Projectile

Ultra-high molecular weight polyethylene (UHMWPE) Dyneema® SK-76 fibers are widely used in personnel protection systems. Transverse ballistic impact onto these fibers results in complex multiaxial deformation modes such as axial tension, axial compression, transverse compression, and transverse shear. Studies on single fibers have showed reduction in tensile strength due to multiaxial deformation and projectile geometry induced stress concentration. In this work, we present the preliminary experimental results of quasi-static multiaxial loading of Dyneema® SK-76 yarns using a 0.30 caliber fragment simulating projectile (FSP) to create a foundation for a failure model. Dyneema® SK-76 yarns are loaded at different yarn starting angles using an FSP projectile and the transverse failure loads are measured. Preliminary experimental results show a little variation in the estimated axial loads with increasing starting angles. This is attributed to the ‘bluntness’ of the FSP’s radius of curvature compared to the diameter of the fibers within the yarn in contact with the projectile.