The objective of this mini-symposium (MS) is to invite presentations on classical and non-classical methods to incorporate the signatures of heterogeneous microstructures into the macroscopic (continuum) material properties for both the linear and non-linear material behavior. Both the theoretical and computational modeling approaches are welcome. This MS is interested in techniques how the visually undetectable micro-anomalies such as micro-cracks and insidious delamination within a small heterogeneous material volume element affect the linear and non-linear material behaviors at the continuum scale. The presence of fluid pressure in such small micro-cracks, that have significant relevance in applications such as 3D printing, nuclear power plants, biological tissue, and geo-materials, is of specific interest for this MS. Presentations, that focus on recent material characterization schemes based on random matrix theory and non-classical continuum theories, are strongly solicited.