Multiscale simulations of three-dimensional nanotube networks: Enhanced modeling using unit cells

This study presents a simulation approach for three-dimensional nanotube networks using cubic and tetragonal unit cells to enhance modeling efficiency. A random-walk algorithm was developed to generate these networks, which were analyzed using a Finite Element Method (FEM) simulation to assess their electrical conductivity. The percolation probability as a function of the nanotube filling factor can be derived from these simulation results. Smaller tetragonal unit cells can replicate the behavior of larger networks with significantly reduced computational effort, achieving up to a 20-fold reduction in computation time while obtaining similar results. In this work, the focus is on carbon-doped titanate nanotubes for hydrogen applications, but the method is adaptable to other applications with similar nanotube network composites. The findings are expected to provide a universal framework for the investigation of nanotube-based materials. • Electrical analysis of 3D realistic nanotube networks using a stochastic simulator. • A unit cell approach provides tremendous potential to reduce time. • Unit cell size and shape have substantial influence on the simulation results.