Progressive damage and failure analysis of CNT-reinforced laminated nanocomposite structures: A multiscale modeling framework

• Developed a framework to predict damage and failure in CNT-reinforced composites. • Integrated nanoscale factors like CNT orientation and waviness into the model. • Combined Halpin-Tsai, Chamis equations, and Hashin’s theory for analysis. • Validated predictions with experimental stress–strain data. • Showed how CNT microstructure affects composite tensile strength. This article presents a Multiscale Modeling Framework for the prediction of the progressive damage and failure analysis of laminated composites structures reinforced with carbon nanotubes (CNTs). First, the modified Halpin-Tsai (H-T) model is employed to estimate the mechanical properties of CNT-reinforced matrix. The H-T equation is capable of distinguishing the difference between micro and nanoscale and accounting for factors such as CNT dispersion and curvature. To capture the CNT and surrounding polymer interactions at the microscale, the Young’s modulus of the isolated CNT is evaluated using the equivalent fiber technique. In addition, the Chamis equations are used to predict the stiffness of the nanocomposite lamina. Then, a set of six equations is developed to estimate the ultimate strength of the nanocomposite lamina based on the individual properties of its constituents, including fibers and the CNT-reinforced polymer matrix. Finally, the damage initiation criterion for Fiber-Reinforced Polymer Composites, based on Hashin’s theory and combined with the fracture energy approach is employed to predict the progressive damage and failure behavior of laminated nanocomposite structures, subjected to tensile loads. This analysis considers the effects of CNT critical factors and size. The predictions of the present Multiscale Modeling Framework are in very good agreement with experimental stress–strain data. It has been demonstrated that while the CNT inclusions can enhance the overall strength of nanocomposite laminae, the tensile strength of the nanocomposite beams is markedly influenced by the microstructural characteristics of CNTs, which significantly reduce the CNTs effectiveness in reinforcing Fiber-Reinforced Polymer Composites.