The effect of strain history on dynamic necking in titanium alloys, experimental and numerical analysis

Abstract

The determination of the dynamic response of titanium alloys is vital for aerospace industrial applications. The present research investigates the effect of strain history and temperature on the dynamic strain localization in Ti-6Al-4V grade-5 alloy. The experimental campaign was conducted using a Split Hopkinson Tensile Bar (SHTB) equipped with an ultra-highspeed camera. The characterization of the material is highly affected once necking occurs. The true dynamic response is compared for various loading conditions. Furthermore, in order to provide insights about on the local dynamic behavior, a numerical model is established using LSDYNAExplicit solver for monotonic loading conditions. Different constitutive material models are compared, including the phenomenological material model Johnson-Cook, and physically based model, Modified BammanChiesa-Johnson (BCJ).