Analysis of geometrical characteristics of CNT-Al composite using molecular dynamics and the modified rule of mixture (MROM)

Abstract

This research presents Molecular Dynamics (MD) simulations to characterize the tensile behaviors of aluminum (Al) composites reinforced with carbon nanotubes (CNTs). The positions, alignments and condensations of CNT inside aluminum composites are stochastic in real and they influence the tensile behaviors of the composites. Thus, it is important to quantize the strengths of the CNT-Al composites depending on the configurations of CNTs. For this, the angles of the CNTs are varied inside an aluminum composite to estimate the yield strengths of the composites using MD simulation. Compared with the strength of pure Al composite, the Young’s modulus of an aluminum composite increases about 20 GPa from 71.52 GPa to 92 GPa (Chiral vector (6,6), 0 degrees). However, with inclined carbon nanotubes, the strength is deteriorated due to the interface slip and the necking of Al block. Some deteriorations of yield stress and yield strain are observed due to premature failure of the CNT–Al composite due to local buckling. In addition, the longitudinal modulus of elasticity was simulated by the number of CNT walls and angle, and as a result, the elastic modulus increased as the number of walls of the nanotube increased, and the material properties of the CNT-Al composite became brittle. We also find out that the modified rule of mixture (MROM) can be used to characterize the effect of geometrical characteristics of SWCNT (Single Wall Carbon Nano Tube)-Al composite.