Computational homogenization of concrete in the cyber Size-Resolution-Discretization (SRD) parameter space

Abstract

Micro- and mesostructures of multiphase materials obtained from tomography and image acquisition are an ever more important database for simulation analyses. Huge data sets for reconstructed 3d volumes typically as voxel grids call for criteria and measures to find an affordable balance of accuracy and efficiency. The present work shows for a 3d mesostructure of concrete in the elastic deformation range, how the computational complexity in analyses of numerical homogenization can be reduced at controlled errors. Reduction is systematically applied to specimen size S, resolution R, and discretization D, which span the newly introduced SRD parameter space. Key indicators for accuracy are (i) the phase fractions, (ii) the homogenized elasticity tensor, (iii) its invariance with respect to the applied boundary conditions and (iv) the total error as well as spatial error distributions, which are computed and estimated. Pre-analyses in the 2d SRD parameter sub-space explore the transferability to the 3d case. Beyond the concrete specimen undergoing elastic deformations in the present work, the proposed concept enables accuracy-efficiency balances for various classes of heterogeneous materials in different deformation regimes and thus contributes to build comprehensive digital twins of materials with validated attributes. • Numerical homogenization analysis for effective elastic properties of concrete specimen. • Comprehensive sampling of the Size-Resolution-Discretization (SRD) parameter space. • Transition from apparent to effective properties invariant to RVE boundary conditions. • Quality of error estimation transferable from 2d to 3d and from small to large volumes. • Considerable efficiency gain in SRD parameter space at controlled errors.