Crack analysis of mesoscale concrete by FEM using an alternative mesh overlay to represent mortar and coarse aggregate

Resumo

One of the main mechanisms of deterioration of concrete structures is cracking. As the shapes of the cracks
are influenced by the heterogeneity of the concrete, when looking for a mechanical model that allows to determine
them realistically, it is necessary to discretize the structure in mesoscale. Using the positional approach of the Finite
Element Method (FEM), this work presents an alternative representation of mesoscale concrete. In this modeling,
the finite element meshes that represent the coarse aggregates and the mortar are generated independently and
overlapped to form the composite material. This strategy aims to make pre-processing easier, the nodes of each
mesh need not be coincident and the degrees of freedom of the elements of the aggregates do not add any unknowns
to the problem. To verify the efficiency of this model, it is applied to the concurrent multiscale analysis of a concrete
sample, leading to responses close to the experimental ones.