Atomically informed nonlocal semi-discrete variational Peierls-Nabarro model for planar core dislocations

Area of Science:

• Materials Science
• Solid Mechanics
• Computational Materials Science

Background:

• Predicting Peierls stress is crucial for understanding crystalline material plasticity.
• Dislocation glide resistance, quantified by Peierls stress, dictates mechanical properties.
• Existing models often lack accuracy for complex dislocation core structures.

Purpose of the Study:

• Develop a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model.
• Incorporate nonlocal atomic interactions into the Peierls framework.
• Accurately predict Peierls stress and displacement profiles for dislocations.

Main Methods:

• Developed a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model.
• Simplified the nonlocal kernel to nearest neighbor interactions.
• Computed the nonlocal coefficient from dislocation core structures.

Main Results:

• The SVPN model accurately predicts displacement profiles.
• The model successfully predicts Peierls stress for planar-extended core dislocations.
• Demonstrated accuracy for dislocations in face-centered cubic structures.

Conclusions:

• The developed SVPN model offers accurate predictions of Peierls stress.
• The model provides a robust framework for studying dislocation mechanics.
• Potential for extension to complex dislocations in intermetallic compounds.