Failure mechanisms of yarns subjected to ballistic impact

Experimental procedures were developed to identify response of virgin yarn material to a ballistic impact event, and to characterize the effect of impact energy in the mode of failure. Various yarn materials were used in the study. Polymeric yarns failed in either a transverse stress wave mode or a shear mode when subjected to ballistic testing. For the para-aramid yarns, a low-impact energy resulted in increased energy absorption compared to a high-impact energy. An increased level of fiber fibrillation was observed at low-impact energies compared to high-impact energies. For the ultrahigh molecular weight polyethylene yarns, a high-impact energy resulted in an increased level of energy absorption compared to a low-impact energy.