Interruption of the strain rate sensitivity of metals at the necking onset

Abstract

In this work, the interaction between the necking onset and the strain rate sensitivity in tensile tests by Split Hopkinson Tensile Bar (SHTB) is investigated. Results from experiments on a FE360 mild steel done by the authors and experimental data available in the literature for a Remco iron are discussed here to investigate the phenomenon. In both cases, images from high speed camera allowed to obtain the true curve of the material, calculating the actual necking section area from the optical measurement of the diameter. Moreover, the implications of such phenomenon on the characterization of materials using an SHTB is discussed.