The objective of this study is to predict the elastic modulus (Ec) of polymer/carbon nanotube (CNT) nanocomposites and to analyze the influence of CNT orientation and volume fraction on their mechanical behavior. A finite element numerical model was developed by considering different CNT orientations (horizontal, inclined, vertical, and random), with volume fractions ranging from 1.39% to 5.58%. The numerical results were compared with analytical micromechanical models commonly applied to short fiber reinforced composites. The findings demonstrate that both CNT orientation and volume fraction have a significant influence on the elastic modulus of the nanocomposite. Increasing the CNT volume fraction leads to a progressive enhancement of the Ec. Horizontally aligned CNTs exhibit the highest elastic modulus (Ec=4799.14 MPa), followed by randomly oriented, inclined, and vertically oriented CNT configurations. The predictions obtained using the finite element method show good agreement with the Halpin-Tsai analytical model. For the horizontal CNT configuration, the results are also consistent with the Cox and Lavngood-Goettler models for certain volume fractions. These results highlight the critical role of CNT orientation and content in enhancing the mechanical properties of polymer/CNT nanocomposites and contribute to the optimization of modeling approaches and material design strategies for these advanced materials.
