A constitutive model for fibre composite materials based on microscopic descriptions

Constitutive equations for composite materials with reinforcing fibres and micro-flaws are derived in the framework of continua with microstructure (multi-field continua). These equations are based on the kinematics and the statics of the material at the microscopic level and account for the geometry and the texture of the material internal phases. Considering homogeneous deformations for the microscopic model (lattice model) the equivalent macroscopic model proves to be a multi-field continuum. Differently from the classical continuous models, this continuum includes internal scale parameters which allow taking into account size effects. The study of a one-dimensional problem points out the influence of the microstructure on the macroscopic behaviour of the composite material.