A sequential homogenization of multi-coated micromechanical model for functionally graded interphase composites

In order to represent the functionally graded properties of interphase, a multi-coated micromechanical model is developed. Based on elliptic shell integration of Green’s function, the strain disturbance in each phase is obtained. According to computational investigation of this model, the outer layer of the interphase does not bring in strain disturbance within the inner ones. To this end, a sequential computational homogenization method is proposed. The inhomogeneities are added sequentially from outside to inside. The temporary effective modulus on each stage is obtained by the Self Consistency Scheme. Then the effective modulus of the overall composites are fitted with a Mori–Tanaka estimation for practical applications. The effectiveness of present method is verified by the results of “2 + 1” and “3 + 1” models in prior researches and finite element simulations. Finally, the influence of thickness and stiffness of interphase on the composites’ effective modulus are investigated.