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

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 severe geometrical imperfections of these material systems, the original formulation presented in Zeman and Sejnoha (2004) is substantially modified, now allowing for nesting and mutual shifting 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 mesoscale porosity through a system of distorted voids. Numerical predictions of both the effective thermal conductivities and elastic stiffnesses provided through the application of the extended finite element method are compared with available laboratory data and the results derived using the Mori-Tanaka averaging scheme to 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.