Implementing van der Waals forces for polytope particles in DEM simulations of clay

TL;DR

This paper develops a method to accurately implement van der Waals forces for non-spherical clay particles in DEM simulations, enabling better modeling of clay behavior at the nano-scale.

Contribution

It extends the Anandarajah solution for van der Waals forces to polytope particles, facilitating shape-accurate force calculations in DEM simulations.

Findings

Extended the Anandarajah solution for cuboid particles.

Enabled shape-accurate force and torque calculations.

Improved DEM modeling of clay particles.

Abstract

Clay minerals are non-spherical nano-scale particles that usually form flocculated, house-of-card like structures under the influence of inter-molecular forces. Numerical modeling of clays is still in its infancy as the required inter-particle forces are available only for spherical particles. A polytope approach would allow shape-accurate forces and torques while simultaneously being more performant. The Anandarajah solution provides an analytical formulation for van der Waals forces for cuboid particles but in its original form is not suitable for implementation in DEM simulations. In this work, we discuss the necessary changes for a functional implementation of the Anandarajah solution in a DEM simulation of rectangular particles and their extension to cuboid particles.