Mesodynamics with implicit degrees of freedom.

Area of Science:

• Computational Physics
• Materials Science
• Multiscale Modeling

Background:

• Atomistic molecular dynamics (MD) simulations are computationally expensive for large systems.
• Mesoscale phenomena bridge the gap between atomistic and continuum scales.
• Existing mesoscale methods often struggle to accurately capture material properties like compressibility and de-cohesion.

Purpose of the Study:

• To develop a computationally efficient mesoscale simulation technique.
• To accurately model compressive and tensile behaviors at the mesoscale.
• To incorporate energy dissipation and transfer between mesoparticles and their internal degrees of freedom.

Main Methods:

• Developed a mesodynamics (MD) simulation technique using mesoparticles instead of atoms.
• Formulated equations of motion derivable from an interaction potential capturing equation of state and de-cohesion.
• Introduced a phase-space formulation for energy transfer between internal and external degrees of freedom, ensuring Galilean invariance.

Main Results:

• The mesodynamics formulation conserves total linear momentum and energy, including internal energy.
• Demonstrated applicability to simulating conduction electrons in metals.
• Successfully applied to model shockwave propagation and thermal transport phenomena.

Conclusions:

• The proposed mesodynamics approach offers a computationally viable alternative to atomistic MD for studying large-scale systems.
• The formulation accurately reproduces essential physical behaviors like energy conservation and momentum transfer.
• Mesodynamics shows promise for diverse applications, including materials science and condensed matter physics.