An adaptive multiscale resolution strategy for the finite deformation analysis of microheterogeneous structures

Standard homogenized formulations of problems posed on microheterogeneous domains provide a lower order of accuracy in regions where highly localized variations are observed in the solution fields. In order to account for this loss of accuracy for the finite deformation analysis of generally inelastic macrostructures, a scale adaptation strategy is developed where a transition from a homogenized description to an explicit microstructural resolution is pursued in designated zones of interest. Motivated by higher-order homogenization techniques, the adaptation zones are identified based on a post-processing step on the homogenized solution and correspond to regions with high strain-gradients. In order to avoid modeling errors emanating from the use of approximate explicit macroscale constitutive formulations, an exact homogenization procedure based on databased and direct multilevel finite element computations is employed. The overall methodology is investigated in a two-dimensional setting where special attention is paid to the underlying multiscale mesh resolution and additionally demonstrated with a three-dimensional problem. Numerical observations suggest the concept of a representative adaptation zone within which scale adaptation effects can be assessed.