Micromechanics-based evaluation of the poroelastic effect and stress concentration in thermochemically-decomposed composites

The poroelastic effect and stress concentration of thermochemically decomposed composites are evaluated based on micromechanics. Considering the pore shapes and array patterns, representative volume elements (RVEs) of homogenized composites are modeled and analyzed using a finite element method. The effects of porosity and material anisotropy are carefully investigated. The poroelastic parameters are calculated based on the pore-pressure-induced strain and effective elastic moduli as well as on the differences between the elastic moduli of solid-skeleton composites and porous composites. The strain energy density is measured to evaluate the microstress concentration caused by pore pressure. Moreover, the effects of constituent phases on the poroelastic parameters and strain energy density are examined by improving the RVE models for heterogeneous composites. The usefulness of the calculation method for poroelastic parameters is investigated through numerical experiments.