Numerical modeling of carbon‐based material systems and related topics

Abstract

This issue is based on the work presented at the minisymposium 'Modeling, Characterization and Analysis of Carbon-based Composite Materials' of the seventh World Congress of Computational Mechanics in Los Angeles (2006). The minisymposium attracted 28 participants from eight countries. Contributions included in this special issue either directly deal with manufacturing and performance of carbon-based composites or consider more general issues that are relevant not only to carbon-based composites but also to a wider class of heterogeneous materials.The first two papers [1,2] are concerned with numerical modeling of chemical vapor depositionthe leading technology for production of carbon-carbon composite materials. Both contributions explore the same kind of phase field methodology to solve the free boundary value problem of chemical deposition, but there are distinctive differences in the form of the local balance equations and in the discretization techniques employed. The balance/constitutive framework developed in [1] contains the Navier-Stokes system augmented with a constitutive equation for the evolution of phase field parameter. The right-hand sides of all balance equations in the system are modified to account for different intensities of the transport process in the solid and gas phases. The discretization of the strongly coupled balance-constitutive system is further performed using the standard finite element method. In [2], a mixed-discontinuous Galerkin formulation is employed for the discretization of the Navier-Stokes equations augmented with a thermodynamically consistent constitutive equation for the phase field. The different intensities of the processes in the solid and gas phases are accommodated without increasing the non-linearity of the right-hand side of the Navier-Stokes system.Contributions [3][4][5] are devoted to numerical analysis of various failure mechanisms in composite materials. Piat et al. [3] investigate stress concentrations and possible fracture initiation due to the nanoscale variations in texture of the pyrolytic carbon matrix around fibers in carbon-carbon composites manufactured by chemical vapor infiltration. The numerical predictions demonstrate good correspondence with experimentally identified failure regions. Lapusta et al.[4] study interaction effects during microbuckling of fiber in fibrous composite materials. Three-dimensional finite element analysis performed in the publication demonstrates the effect of fiber anisotropy on critical shortenings. It also shows that fiber interaction results in a significant increase in the buckling wavelength. Tsotsova [5] proposes a variational approach to the identification of cracks in linear elastic materials based on measurements performed on the surface of the solid (inverse crack identification problem). The approach is illustrated by a sample finite element simulation; good convergence of the proposed iterative procedure is shown.Finally, contributions [6,7] propose novel computational techniques to model non-simultaneous...