Abstract
Nanoscale material carbon nanotubes (CNTs) have been widely investigated due to their ultrahigh Young's modulus, thermal conductivity, and other notable properties. This study seeks to employ a model to investigate both atomic-scale and nano-scale models for tensile and modal analysis based on the atomistic-continuum mechanics (ACM) and the finite element method. ACM transfers an originally discrete atomic structure into an equivalent continuum model. The unique feature of ACM is its ability to use the same model for tensile and modal analysis without requiring prior input. Young's modulus, cross-sectional area, and density are not required in the modal analysis of ACM. Compared with other results published in literature, the Young's modulus in the ACM model is reliable and acceptable. According to composite material mechanics, material properties depend on the features of the fiber and the matrix. Several studies have indicated that the Young's modulus of CNT fibers depend on the diameter of the fiber. However, some studies do not support this finding, claiming that the Young's modulus depends on the cross-sectional area arrangement of CNT fibers, such as whether a solid or hollow cross-sectional area is adopted. Overall, the validity of the results is demonstrated with comparisons to numerical and experimental results provided in literature; this has been done to ensure model accuracy and to reduce simulation time of the central processing unit. Therefore, the composite material within CNTs could be simulated using ACM and equivalent methods. In addition, the Young's modulus and the thermal conductivity of the composite material depend on the direction of the CNT fibers.