Modeling laser-driven high-rate plasticity in BCC lead
Abstract
We discuss the constitutive modeling of lead in the high-pressure body-centered cubic (bcc) phase. Constitutive models for lead in the literature are calibrated to experiments in the low-pressure face-centered cubic (fcc) phase. The Steinberg-Guinan model for pure lead is one such model. As an assessment of the effect of different crystal structure at high pressure, we construct a model for the bcc phase. The model is in the Improved Steinberg-Guinan form, with the pressure hardening determined by first-principles calculations of the pressure dependence of the shear modulus. The constitutive models have been run in continuum simulations of high-pressure deformation experiments as a test of the models. High-energy laser platforms such as the National Ignition Facility (NIF) can probe plasticity at extremely high pressures and rates in largely shock-free ramp-compression waves. Here we consider experiments on lead at peak pressures of ∼350-500 GPa and strain rates of ∼ 107/s.
- Publication:
-
Shock Compression of Condensed Matter - 2017
- Pub Date:
- July 2018
- DOI:
- 10.1063/1.5044836
- Bibcode:
- 2018AIPC.1979g0027R