EFFECTIVE ELASTIC PROPERTIES OF NANOTUBE REINFORCED COMPOSITES WITH SLIGHTLY WEAKENED INTERFACES

In this paper a micromechanics approach is presented for determining the effective elastic properties of single-walled carbon nanotube (SWCNT) reinforced composites, while accounting for imperfect bonding in the matrix-inclusion interface. For this purpose, a linear spring layer of vanishing thickness is introduced to represent the interface. Furthermore, the well known Mori-Tanaka (MT) method, in conjunction with the Eshelby's tensor, is modified to determine the effective elastic properties. The inclusions are considered to be either perfectly aligned infinite long cylinders or aligned ellipsoidal inclusions with a given aspect ratio; cases of perfect alignment or of randomly oriented fibers are treated. The numerical results show that the interface weakening influences the nanocomposite properties significantly only for high values of SWCNT volume fraction. Since most of the currently conducted experiments involve composites which contain small volume fractions, it is thus reasonable based on the findings of this paper to assume perfect bonding for low nanotube volumetric contents.