Molecular Structural Finite Element Analysison Single-walled Carbon Nanotubes

In the 21 st century, a new era began with the third industrial revolution, the nanotechnology and nano materials have become the leader of the new material technology. Carbon nanotubes(CNTs), one of these nanotechnology and nano materials, are becoming the best of the best in this field. Carbon nanotubes show some properties, which are different from ordinary materials’, including mechanical, electrical, optical, and thermal and so on. Exactly, because of these distinctive properties, carbon nanotubes have the application value that other materials cannot match.In order to study the mechanical behaviors of carbon nanotubes, based on the molecular structural mechanics method proposed by Li Haijun and Guo Wanlin, the author achieves finite element method and simulation of CNTs in the generous FEM software ANSYS. In this thesis, at first, the author introduces the molecular structural mechanics. Then some simulation methods and programs are developed in the ANSYS, using the secondary development technology. In this process, the covalent bond of carbon atoms is modeled by beam element.Firstly, the author sets up finite element model of single wall carbon nanotubes. Then, finite element analysis using the model was carried out to study the elastic behavior of single-walled carbon nanotubes. Meanwhile, the elastic modulus of single-walled carbon nanotubes is calculated. Also, the author analyzes the relationship between the modulus of elasticity and the structural parameters(diameter and chiral angle). Finally, finite element analysis is used in studying the vibration characteristics of single-walled carbon nanotubes with the established model. Calculating the inherent frequency and vibration mode of the single-walled carbon nanotubes, and analyzing the relationship between natural frequency and structure parameters(length and diameter), the author summarizes four kinds of vibration mode of single-wall carbon nanotubes.