Structural modeling and mechanical research of carbon nanotube reinforced aluminum matrix composites using strain gradient theory

Carbon nanotube (CNT)-reinforced aluminum alloys (Al) are considered to be the ideal metal-matrix composites owing to their high strength and elastic moduli. However, they have low ductility. In addition, the inhomogeneity of the structure makes a strong strain gradient during deformation. In this research, a series of simulations under uniaxial tension and shear loading paths were conducted to investigate the mechanical properties of CNT/Al6061 composite. The novel multiple mechanism-based strain gradient models (MMSG) were proposed to study and analyze the correlation between microstructure evolution and macro mechanical responses. The interfacial bonding, grain size, and dislocation density were mainly considered during the simulation. The results of this study can be used to reveal the synergetic strength and ductility of all the structural microstructure, which also affects the strain partition and failure of different phases in CNT/Al6061 composites.