Ultra-High Strain Rate Constitutive Modeling of Pure Titanium Using Particle Impact Test

Abstract

Abstract With the advent of advanced testing techniques such as laser-induced particle impact test, it is possible to study materials mechanics under extremely high deformation rates, i.e., above 106 s−1, a relatively less explored regime of strain rates. Inspired by the classical Taylor impact test, in this study, we accelerate microparticles of commercially pure titanium to a range of impact velocities, from 144 to 428 m/s, toward a rigid substrate and record their deformation upon impact in real-time. We also conduct finite element modeling of the experimentally recorded impacts using two constitutive equations, namely, Johnson–Cook and Zerilli–Armstrong. We show that the titanium microparticles experience strain rates in the range of 106–1010 s−1 upon impact. We evaluate the capability of the Johnson–Cook and Zerilli–Armstrong equations in predicting the deformation response of pure Ti at ultra-high strain rates. With an optimization-based constitutive modeling approach, we also propose updated strain rate-related parameters for both equations and improve the extent to which the two models can describe the deformation of pure titanium at ultra-high strain rates.