كليدواژه :
Timoshenko beam theory , Nanotubes , Nanotube , buckling of CNTs , chirality effect
چكيده فارسي :
Although the special geometrical and mechanical properties of carbon nanotubes (CNTs) make them suitable for various applications, some types of loading lead to buckling them which reduces their high-resolution ability and deteriorates their other performances. Therefore, the study of CNT buckling is an important topic. Based on the nonlocal Timoshenko beam theory, buckling behavior of triple-walled zigzag and armchair CNTs whose aspect ratios are more than 10 is investigated and the effects of aspect ratio, existence of elastic medium, lattice translation integer indices and small scale on the axial buckling behavior of CNTs are evaluated. On the other hand, the buckling behavior of armchair and zigzag CNTs with little difference in their inner radius, are contrasted to each other. Results show that although small scale decreases the predicted value of the critical axial force, chirality, aspect ratio and existence of elastic medium influence it. It is found that by increasing aspect ratio, not only the effect of chiral indices on the critical axial force of embedded CNTs is preserved but also the load-bearing capacity of CNTs tends to a fixed value.