Molecular Dynamics Analysis And Cellular Automation Of Carbon Nanostructure

Carbon nanomaterials exhibit exceptional mechanical properties due to their high concentration of interfaces,which are often absent in bulk materials.Carbon nanotubes and graphene,with their perfect structure,small size,and low density,possess outstanding mechanical and physical characteristics.These unique properties have led to widespread applications of carbon nanomaterials in various fields.Cellular automaton(CA)models offer advantages in simulating complex systems due to their inherent parallelism.Additionally,the principle of minimum potential energy is a widely applicable rule in both macroscopic natural phenomena and microscopic systems.In this study,we combine these two concepts and develop a cellular automaton model suitable for nanoscale simulations based on molecular mechanics.The model is used to investigate the mechanical properties of carbon nanomaterials.The main aspects of this research include:First,introduction of the Tersoff many-body potential to establish a cellular automaton model applicable to carbon nanomaterials.Taking the example of tensile deformation of defective single-walled carbon nanotubes,we compare the simulation results of the cellular automaton under displacement and force loading.The simulated tensile fracture processes exhibit good consistency,and the calculated mechanical parameters(fracture strain,maximum stress,and Young’s modulus)show small relative errors.We also compare the simulation results of the cellular automaton under displacement loading with those of molecular dynamics simulations,which also show good agreement.Based on these comparisons,the correctness and effectiveness of the cellular automaton model are verified.Then,application of the established cellular automaton model to study the static mechanical response of monolayer graphene.Through cellular automaton simulations of tensile and compressive loading of monolayer graphene,we find that tension leads to tearing along the loading direction without wrinkling,while compression induces wrinkling of the graphene sheet.Furthermore,after reaching a certain load level,the hexagonal honeycomb structure around the loading region is disrupted.Finally,to investigate the mechanical response between different carbon nanomaterials,we design interactions between carbon nanotubes and graphene in two different orientations.Molecular dynamics and cellular automaton numerical simulations reveal that carbon atoms on the nanotubes can attract carbon atoms on the graphene sheet,leading to the formation of stable new carbon-carbon bonds.This results in a three-dimensional carbon nanomaterial composed of one-dimensional carbon nanotubes and two-dimensional graphene,which exhibits favorable mechanical properties.