# Computational Study of Ultrathin CNT Films with the Scalable Mesoscopic Distinct Element Method

## TL;DR

This study uses a scalable mesoscopic simulation method to analyze the small strain mechanics of ultrathin carbon nanotube films, revealing how energy dissipation during CNT sliding influences their mechanical behavior.

## Contribution

It introduces a detailed mesoscopic modeling approach for large CNT assemblies, incorporating realistic inter-tube interactions and deformation mechanisms.

## Key findings

- Energy dissipation during CNT sliding extends load transfer.
- CNT films exhibit material-like mechanical response due to weak bonding.
- The simulation provides insights into the micro-mechanical behavior of CNT assemblies.

## Abstract

In this work we present a computational study of the small strain mechanics of freestanding ultrathin CNT films under in-plane loading. The numerical modeling of the mechanics of representatively large specimens with realistic micro- and nanostructure is presented. Our simulations utilize the scalable implementation of the mesoscopic distinct element method of the waLBerla multi-physics framework. Within our modeling approach, CNTs are represented as chains of interacting rigid segments. Neighboring segments in the chain are connected with elastic bonds, resolving tension, bending, shear and torsional deformations. These bonds represent a covalent bonding within CNT surface and utilize Enhanced Vector Model (EVM) formalism. Segments of the neighboring CNTs interact with realistic coarse-grained anisotropic vdW potential, enabling relative slip of CNTs in contact. The advanced simulation technique allowed us to gain useful insights on the behavior of CNT materials. In particular, it was established that the energy dissipation during CNT sliding leads to extended load transfer that conditions material-like mechanical response of the weakly bonded assemblies of CNTs.