Damage Models for Micromorphic Continuum

Resumo

Numerous materials, although they appear macroscopically homogeneous, usually present a heteroge-
neous microstructure that directly influences the structural behavior. The phenomenological approach followed by

the classical continuum mechanics does not individually accounts for this influence, which can be significant, for
example, in cases where the structure or the specimen under analysis is small compared to its microstructure or
when the material media has a complex microstructure. Within the framework of continuum mechanics, so-called

generalized continuum theories are particularly suited to deal with the above issues incorporating the microstruc-
tural behavior on the formulation. The micromorphic theory is included in this general class of generalized con-
tinua and, more specifically, in the group that incorporates additional degrees of freedom to the material particles.

Another aspect of generalized continua is its ability to address the issue of localization in quasi-brittle materials
modeled as elastic-degrading media as a result of its non-local character. In order to allow the representation of
quasi-brittle media with the micromorphic continuum theory, this work presents a formulation for scalar-isotropic

damage models for a micromorphic continuum in the constitutive models framework of the INSANE system, ini-
tially conceived for classical media and later expanded for the micropolar continuum. This implementation is based

on the tensorial format of a unified constitutive models formulation and homogenization techniques to obtain the
micromorphic constitutive relations.