Fully periodic RVEs for technological relevant composites: Not worth the effort!

The setup of a finite element model for homogenization featuring a fully periodic geometry and a fully periodic mesh topology in combination with a high quality discretization is a cumbersome task and might significantly reduce the overall efficiency in multiscale finite element simulations. In this work, we examine multiple methodologies of setting up finite element models for homogenization purposes that extenuate these difficulties. Approaches resulting in periodic and nonperiodic representative volume element topologies in the microstructural generation process are introduced. Furthermore, we review and analyze various types of boundary conditions that either enforce periodicity or do not require periodicity of the underlying discretization. Approximate periodic boundary conditions are discussed in detail. The benchmark study proves that a fully periodic topology and mesh discretization with periodic boundary conditions is not necessary in order to identify effective macroscopic material parameters for technologically relevant composites.