The role of defected/wavy/aggregated CNTs on the wave propagation in size-dependent nanocomposite beams

Abstract

Lack of attention to the real structure of nanocomposites such as agglomeration of nanotubes, defects in nanotubes, and curvatures of their structures can be the reason for inaccuracies in the modeling of nanocomposites. Here, a few steps have been taken to bring these models closer to reality. Three modifications will be studied in this article. According to this fact that nanotubes, as fibers in nanocomposites, do not necessarily have straight structure and they have curvatures. Their curliness was included in the present model. Obviously in reality, when nanotubes are produced, they have defective structures and this can be a reason for including the defective nanotubes in the present model for nanocomposites. Finally, it is clear that the production of nanocomposites is not perfect and contrary to expectations, there may be problems when manufacturing nanocomposites. One of these problems is the agglomeration of nanotubes, which will be examined in this article. Also, strain gradient theory and nonlocal elasticity theory are used to capture the size effects on these types of nanocomposites which have not been considered yet for nanocomposite beams. From present results, it is concluded that increasing the agglomeration volume of CNTs will increase the circular frequencies.