The Damage Process Monitoring in Structures with Quasi-Brittle behavior in the perspective of Complex System

The damage process in structures with quasi-brittle behavior, such as concrete, rocks, ceramics, and composites, is characterized by typical phenomena including sensitivity to size effect, the interaction of micro-fissures, and the transition of the continuum to discontinuity through the so-called localization effect. There are many approaches to modeling the mechanical behavior of this type of material/structure. Our simulation strategy, which is a version of the discrete element model, aligns with Prof. Krajcinovic's perspective. According to him, the random nature of the material is a key aspect that must due to consider. With the aim of addressing this problem, the Acoustic Emission Technique (AET) could also be useful to characterize the damage process. The spatial and temporal distribution of events during the damage process is determined by the combination of signals captured from different locations in the structure. This information can be used to calculate global parameters and their evolution during structural damage. These parameters may serve as precursors to identify local or global damage. It is worth noting that structure failure can be viewed as a phase transformation phenomenon. The Renormalization Group Theory, proposed by Wilson, and Anderson's ideas related to complex systems provide a theoretical perspective that allows us to understand the collapse in solids from a different angle. The present work considers some applications related to the characterization of the damage process of quasi-brittle structures/materials, carried out by our research group. We aim to establish a link between these results and the ideas of Wilson and Anderson.