Análise do efeito unilateral de microestruturas danificadas dentro de uma abordagem multiescala

Abstract

Numerical analysis of the mechanical behavior of composite materials, taking into account the specificity of each of their phases, requires complex models that sometimes lead to unfeasible analyses. Thus, the present work deals with modeling the mechanical behavior of damaged and fractured heterogeneous granular materials within a multiscale approach with the aim of simulating the mechanical behavior of materials, especially concrete, as well as the unilateral effect due to their behavior under loads with inversion of loading. The modeling, in turn, is based on the concept of the Representative Volume Element (RVE) representing the concrete microstructure, using the Finite Element Method (FEM) to obtain the solution to the computational homogenization equilibrium problem proposed here. The matrix is considered a damaged material according to the Mazars damage model. Linear elastic behavior is adopted for the inclusions. To represent the transition zone, several strategies are considered, from cohesive and contact fracture elements to high aspect ratio element models modified in this work. Another aspect worth highlighting in this work is the formulation for the homogenization of RVE damage, which was developed for simplicity using the concept of hierarchical multiscale analysis. Finally, results of representative microstructures of concrete subjected to macroscopic states of deformation are presented, and the homogenized responses obtained show the expected behavior of the concrete, including a comparison with the experimental response of the concrete.