Atomistic simulations of the buckling behavior of perfect and defective silicon carbide nanotubes

In the present study, the buckling behavior of silicon carbide nanotubes (SiCNTs) is investigated employing molecular dynamics (MD) method. The structural properties of material are appropriately described using the Tersoff potential. Initially, effective Young’s modulus of armchair and zigzag SiCNTs are calculated. The present results show that the effective Young’s modulus of SiCNTs is weakly affected by the tube chirality and the tube diameter. After validating the MD model, it is extended to examine the buckling behavior of perfect SiCNTs for different lengths under axial compression. The developed results demonstrate that two types of buckling modes are existed corresponding to the different lengths, named as local and global modes. In the local buckling mode, a little variation of critical buckling load with length of SiC nanotubes is achieved, but this variation is considerable for the global buckling mode. Furthermore, the critical buckling loads of defective SiCNTs due to the axial compressive load at different temperatures are compared with those of the perfect structures. The simulations reveal that the buckling load of perfect SiCNTs decreases significantly with the increase of environmental temperature. It is also observed that the effect of temperature on the buckling loads of perfect SiCNTs is greater than those of defective nanotubes. The computational results exhibit that regardless of the chirality, the load capability is weakened more by the vacancy type defects compared with the antisite defects.