Molecular Dynamics Of Nontypical Buckling Behavior Of Boron Nitride Nanotubes

Boron nitride nanotubes(BNNTs)have excellent mechanical,electrical and high temperature performance.Molecular dynamics(MD)is a kind of computer simulation method widely used in nanoscience and technology.And it has irreplaceable advantages in the simulation and quantitative description of nanostructured systems.In this paper,the molecular software Lammps and VMD software are used to simulate the nontypical buckling behaviors of single-wall BNNTs via MD.In this paper,MD simulation is utilized to study the buckling behaviors of BNNTs under two simple loads of axial compression and torsion respectively.The buckling and post-buckling configurations of BNNTs are presented.The effects of the chirality,temperature,radius and length on the buckling behaviors are also studied.It is found that different chiral BNNTs nearly share the same buckling modes.And under simple loads,temperature has a significant effect on the mechanical behavior of BNNTs.The results also show that the buckling behaviors are size dependent.Also,the buckling behaviors of BNNTs under combined axial compression and torsion are researched.The mechanical behavior under combined loads is compared with that under simple loads.The critical curves of nanotubes with different temperatures,radii and lengths are plotted respectively.The results show that the buckling behavior of BNNTs are also size dependent.And the critical buckling stress decreases with the increase of radius or length.Moreover,the increase of temperature will also decrease the ability of anti-resistance.Both the armchair and zigzag BNNTs exhibit nonlinear critical buckling load relations.The buckling behaviors of BNNTs with Stone-Wales(SW)defects under axial compression,torsion,combined axial compression and torsional are simulated by MD.The location of the defect is included the middle part of the tube,the top part,and the combination top and middle part.The influence of temperature,length and radius on the buckling behaviors of BNNTs with SW defects is investigated.The results show that SW defect reduces the ability of BN nanotubes to resist buckling load,and BNNT with SW defect in the middle part presents lower critical load values than BNNT with SW defect in the top part.Moreover,for different locations of defects,the two chiral BNNTs exhibit nonlinear critical buckling load relations.