Attempt to Evaluate the Mechanical Behavior of Pure Iron Under an Instrumented Taylor Impact Test

Abstract

Although the instrumented Taylor impact (ITI) test has been extended to measure the unknown mechanical behavior of pure aluminum at ultra-high-speed impact, it remains uncertain whether the important assumption that internal force distributes linearly in certain regions holds for other materials. Hence, in this work, pure iron, whose deformation behavior at ultra-high-speed impact remains unknown due to the speed limitations of existing methods, is introduced into the ITI test to verify the assumption and attempt to evaluate its mechanical behavior. The assumption is verified using the digital image correlation (DIC) method. Unlike the pure aluminum specimen, the assumption holds for a relatively longer time period in the case of pure iron. According to the experimental results, a previously uncaptured high frequency component in the impact force wave is newly discovered using a polyvinylidene fluoride (PVDF) film instead of a strain gauge. Hence, the impact force wave should be measured using a PVDF film rather than a strain gauge. The shock wave is observed for the first time in the ITI test using a pure iron specimen. Additionally, a previously unreported opposite pulse in the impact force wave was newly observed in the ITI test, implying that the magnetic properties of the material might have changed.