Molecular dynamics simulation for determining dislocation strengthening coefficient in BCC iron

Crystal plasticity models are promising numerical analysis methods for predicting and evaluating material forming processes. In crystal plasticity analyses, the dislocation density model, often based on the Bailey-Hirsch equation, is employed to represent the work hardening behavior of metallic materials. The dislocation strengthening coefficient is a proportional factor between the square root of dislocation density with the slip resistance. Therefore, the appropariate determination of the dislocation strengthening coefficient is crucial to perform reliable material forming analyses using crystal plasticity models. Previously, dislocation strengthening coefficients have been determined using dislocation dynamics simulations. However, dislocation dynamics simulations cannot accurately account for elastic anisotropy due to its computational cost. To address this limitation, we conducted molecular dynamics simulations to determine dislocation strengthening coefficient in bcc iron. Molecular dynamics simulations of dislocation-dislocation interaction analysis can be expected to determine the dislocation strengthening coefficient accurately, including the effects of elastic anisotropy of metallic materials.