  To reduce reliance on experimental fitting data within the crystal plasticity
finite element method (CPFEM), an approached is proposed that integrates
first-principles calculations based on density functional theory (DFT) to
predict the strain hardening behavior of pure Ni single crystals. Flow
resistance was evaluated through the Peierls-Nabarro equation using the ideal
shear strength and elastic properties calculated by DFT-based methods, with
hardening behavior modeled by imposing strains on supercells in
first-principles calculations. Considered alone, elastic interactions of pure
edge dislocations capture hardening behavior for small strains on single slip
systems. For larger strains, hardening is captured through a strain-weighted
linear combination of edge and screw flow resistance components. The rate of
combination is not predicted in the present framework, but agreement with
experiments through large strains (~0.4) for multiple loading orientations
demonstrates a possible route for more predictive crystal plasticity modeling
through incorporation of analytical models of mesoscale physics.
