Aluminum alloys and aluminum-based composites possess a unique set of properties making them excellent candidates for many applications in structural, aerospace, automobile, defense, high-tech industries, etc. Among all aluminum alloys, aluminumcopper ‘Al-Cu’ alloy has the highest strength and hardness at elevated temperatures. Hence it was the topic of interest of many researchers leading to a wide data reported for its potential functions’ parameters. Yet, the increase in the stiffness is minimized and needs to be enhanced by reinforcing it with other materials like carbon nanomaterial and developing metal-based composites. Carbon nanotubes ‘CNTs’ due to their novel properties have attracted a great deal of interest as a reinforcement in polymeric, ceramics and metal-based composites. Numerical investigation through the use of molecular dynamics simulation ‘MD’ and hierarchical multiscale modeling are used for the first time to study the mechanical properties of aluminum-copper alloy reinforced with carbon nanotube nanocomposite ‘Al-Cu/CNT’. The aim is to investigate the mechanical properties of the nanocomposite at the atomistic scale using MD simulation then use hierarchical multiscale techniques to scale up the properties by homogenization to the microscale and use finite element method ‘FEM’ to find the properties of the nanocomposite at the microscale. A molecular dynamics simulation model was created to examine the mechanical properties of Al-Cu/CNT nanocomposite using the open-source software LAMMPS. To start with, the model was validated by creating two MD models and comparing their results to results published in the literature. The first model was for aluminum reinforced with CNT ‘Al/CNT’, and the second model was for aluminum copper alloy 'Al-Cu’. Visual molecular dynamics ‘VMD’ software was used to create the structure of the CNT, whereas LAMMPS software was used to create the structure of the Al and Al-Cu matrices. To fully understand the mechanical properties of the nanocomposite, a parametric study was conducted where the mechanical properties of the nanocomposite were studied under the influence of several parameters. Those parameters include the size of the CNT, volume fraction of the CNT, structure of the CNT (armchair, zigzag, and chiral), aspect ratio (length to diameter ratio) of the CNT, and applied strain rate. Additionally, the effect of material distribution of Al-Cu alloy on the mechanical properties of the nanocomposite was considered by functionally grading the alloy. All the above parameters are studied independently of each other, meaning that when the effect of the size of the CNT for example is considered all other parameters are kept fixed. This is done to ensure that the change in the mechanical properties is only due to that parameter. The volume fraction of the CNT was increased from 1% to 10% for a nanocomposite with a 10% alloying of Cu reinforced with an armchair CNT having a chirality of (6,6). The modulus of elasticity and the failure strength were found to increase remarkably as the volume fraction increased but no change was noticed on the failure strain of the nanocomposite. An increase of 76% and 150% in the modulus of elasticity and the failure strength, respectively, were observed as the volume fraction increased from 1% to 10%. By increasing the size of the CNT and hence increasing its diameter, the modulus of elasticity and the failure strain were both found to decrease along with the yield and failure strengths. A decrease of almost 30.8% and 32.6% were calculated for the yield and failure strengths, respectively, as the size of the CNT increased from (6,6) to (12,12). The failure behavior was observed to vary with respect to the structure of the CNT. Both the armchair and zigzag CNTs exhibited a similar behavior where a sudden failure of the nanocomposite was observed, whereas in the chiral CNT, the failure was gradual. The nanocomposite with the armchair CNT was found to have the highest modulus of elasticity and failure strain. Regarding the aspect ratio and the applied strain, no significant difference was noticed in the modulus of elasticity of the nanocomposite due to either. A very slight increase was noticed in the failure strain as the applied strain rate was increased. Furthermore, sigmoid distribution was used to functionally grade the AlCu alloy in the longitudinal direction, and the molecular dynamics results revealed that the material distribution has almost no effect on the mechanical properties of the nanocomposite. A hierarchical multiscale simulation method was then used to find the mechanical properties of the Al-Cu alloy reinforced with a (6,6) armchair carbon nanotube nanocomposite at the microscale. Molecular dynamics simulation using LAMMPS software was first used to calculate the five mechanical properties of the nanocomposites namely, the longitudinal ‘EL’ and transverse ‘Ex’ moduli of elasticity, the Poisson’s ratios in x-y ‘𝜈xy’ and x-z planes ‘𝜈xz’, and the shear modulus ‘G’. The Al-Cu/CNT nanocomposite was then homogenized into an equivalent fiber with the exact same structure and properties, where the latter was embedded in multiple numbers following a hexagonal arrangement into an Al-Cu matrix with 10% alloying. Perfect bonding between the equivalent fiber and the matrix was assumed. The finite element method was then implemented on a representative volume element ‘RVE’ to find the five mechanical properties of the nanocomposite (EL, Ex, 𝜈xy, 𝜈xz, G) at the microscale under the effect of the volume fraction of the CNT using APDL ANSYS software. Results showed that the longitudinal modulus of elasticity along with the Poison’s ratios in the x-y and x-z planes increased as the volume fraction of the CNT increased. However, both the transvers modulus of elasticity and the shear modulus exhibited a very slight decrease in their value as the volume fraction of the CNT increased.