Abstract:Based on the theory of Gurtin-Murdoch surface/interface theory and the generalized self-consistent method, the closed-form solution of the effective anti-plane shear modulus of the nano coated fiber reinforced composites is obtained. The effects of wall thickness, mechanical property and interfacial property of the coating on the effective property of the composites are discussed. The numerical results reveal that the effective modulus is size dependent when the size of the coating is on the order of nanometer. For a fixed fiber volume fraction, the thinner the wall thickness is and the smaller the fiber radius is, the greater of the deviation is with the classical results. The influences of the fiber stiffness and coating interfacial property on the effective modulus are dependent on the coating stiffness, i.e., a very soft or very hard coating can shield the contribution of the fiber stiffness to the effective modulus of composites, and a very hard coating shields the surface/interface effect of the nano composites.