Two-step hierarchical micromechanics model of partially saturated porous composites doped with ellipsoidal particles with interface effects

Recent advances in the manufacture of micro- and nano-composites have made it possible to produce new multifunctional materials. However, the development of theoretical models that assist their design still remains an open research issue. This paper presents a two-step hierarchical micromechanics approach for the mechanical homogenization of particle-reinforced porous composites, including particle/matrix interfacial bonding and porosity saturation effects. Firstly, the particle-reinforced matrix is homogenized by means of a double-inclusion approach. The interfacial bonding effect is accounted for by both compliant and hard interphases surrounding the particles. Secondly, another homogenization step is conducted by considering the particle-reinforced composite as a homogeneous matrix and voids as embedded inclusions. Pores saturation is also taken into account by means of homogeneous equivalent pores. Comparative analyses against experimental data are presented to demonstrate the effectiveness of the present approach, followed by detailed parametric analyses to illustrate the influence of the major micromechanical variables, including interphase thickness and stiffness, filler aspect ratio, porosity and saturation degree.