MOLECULAR DYNAMICS SIMULATIONS OF THE MECHANICAL BEHAVIOR OF TWO-PHASE POLYMERS (original) (raw)

Abstract To realize the incredible structural applications potential of carbon nanotubes, it is important to characterize their material response. Molecular simulations offer advantages over physical testing due to their cost effectiveness, versatility and precision. Two continuum models for single wall nanotubes (SWNT) were previously developed based on the results from molecular simulations using two different potentials. The continuum models have been found to predict both global and local responses for buckling well.

https://www.ijert.org/molecular-dynamics-simulation-of-carbon-nanotubes https://www.ijert.org/research/molecular-dynamics-simulation-of-carbon-nanotubes-IJERTV2IS80533.pdf Elastic properties of single walled carbon nanotubes (SWCNTs) have been determined using molecular dynamics (MD) simulation. Mechanical properties of three types of SWCNTs viz., armchair, zigzag and chiral nanotubes have been evaluated. From computational results, it can be concluded that the Young"s moduli of SWCNTs decrease with increase in radius of SWCNT and increase with increase in CNT volume fractions (V f) and aspect ratios (l/d).

Since their discovery in 1991, both single wall and multiwall carbon nanotubes have become an active area of research. This is partly due to their having an extremely high specific strength and stiffness. These properties and their cylindrical shape allow for their potential applications in such diverse fields as fibrous reinforcement, atomic level piping, and nanostructures. The structural applications of carbon nanotubes require that we ascertain their macroscopic properties.

Carbon nanotubes have caught tremendous attention of the researchers during the last decade due to their excellent mechanical, electrical, optical and thermal properties. The exploitation of these fibers as reinforcing agents in making strong fiber composites has been a primary research topic in the recent investigations on composite materials. Although the theoretical results are rather optimistic, the goal of achieving high strength of the carbon nanotube composites is still not satisfactorily realized. We report here a comparative study of the mechanical properties of single-walled, multi-walled and bundle of single-walled carbon nanotubes. Their mechanical behavior is investigated by molecular dynamics simulation, considering Brenner’s second generation reactive empirical bond order interatomic potential between the carbon atoms making a tube. For a long range interaction, we have defined a weak van der Waals force which acts between different layers of a multi-walled tube or between different tubes of a bundle. Samples of three isolated armchair single-wall carbon nanotubes of different diameters, a multi-wall armchair carbon nanotube and finally a bundle of three armchair single-walled nanotubes of same diameter are taken. Their fracture pattern and buckling behavior are modeled and compared. Significant changes are observed in the mechanical properties of the samples of different types of carbon nanotubes which arise due to the interaction between the shells of a multi-walled tube or the tubes in a bundle.