Homogenization of plain weave composites with imperfect microstructure: Part II--Analysis of real-world materials

TL;DR

This paper develops an advanced homogenization model for plain weave composites that accounts for real-world imperfections, including layer shifts and porosity, and validates it against experimental and numerical data.

Contribution

It introduces a modified two-layer unit cell model that captures geometrical imperfections and meso-scale porosity, improving prediction accuracy for composite properties.

Findings

Model accurately predicts thermal conductivities and elastic stiffnesses.

Comparison with laboratory data validates the model's effectiveness.

Incorporation of porosity and layer shifts enhances realism of predictions.

Abstract

A two-layer statistically equivalent periodic unit cell is offered to predict a macroscopic response of plain weave multilayer carbon-carbon textile composites. Falling-short in describing the most typical geometrical imperfections of these material systems the original formulation presented in (Zeman and \v{S}ejnoha, International Journal of Solids and Structures, 41 (2004), pp. 6549--6571) is substantially modified, now allowing for nesting and mutual shift of individual layers of textile fabric in all three directions. Yet, the most valuable asset of the present formulation is seen in the possibility of reflecting the influence of negligible meso-scale porosity through a system of oblate spheroidal voids introduced in between the two layers of the unit cell. Numerical predictions of both the effective thermal conductivities and elastic stiffnesses and their comparison with available laboratory data and the results derived using the Mori-Tanaka averaging scheme support credibility of the present approach, about as much as the reliability of local mechanical properties found from nanoindentation tests performed directly on the analyzed composite samples.