Single Fiber Tensile Properties Measured by the Kolsky Bar Using a Direct Fiber Clamping Method

Abstract

The Kolsky bar test has been widely used in measuring material behavior under high strain rate conditions. In particular, polymers used in ballistic applications have been characterized by this method to investigate high strain rate behavior during ballistic impact. Research conducted by Cheng et al. (J Eng Mater Technol-Trans ASME 127(2):197–203, 2005) and Lim et al. (J Mater Sci 45(3):652–661, 2010) measured high strain rate properties of single PPTA [Poly (p-phenylene terephthalamide)] fibers and aramid co-polymer fibers by gluing the fiber directly to the Kolsky bar, which is time consuming work and can be affected by wicking of the glue into the fiber gauge length area. Kim et al. (J Mater Sci. doi: 10.1007/s10853-013-7142-y, 2013) investigated clamping effects of the glue-tab and direct gripping methods on the single PPTA fiber tensile properties under the quasi-static loading condition and applied the direct grip method for the Kolsky bar test to measure the tensile strengths at a high strain rate (Kim et al., Compos Sci Technol. doi: 10.1016/j.compscitech.2012.03.021, 2012). This study extends the measurement capability for the tensile strength, failure strain and modulus that are important parameters that influence performance of soft body armor.