CONICET | Buscador de Institutos y Recursos Humanos

A new formulation to model the mechanical behavior of high performance fiber reinforced cement compositeswith arbitrarily oriented short fibers is presented.The formulation can be considered as a two scale approach, in which the macroscopic model, at thestructural level, takes into account the mesostructural phenomenon associated with the fiber?matrixinterface bond/slip process. This phenomenon is contemplated by including, in the macroscopic description,a micromorphic field representing the relative fiber?cement displacement. Then, the theoreticalframework, from which the governing equations of the problem are derived, can be assimilated to a specificcase of the material multifield theory.The balance equation derived for this model, connecting the micro stresses with the micromorphicforces, has a physical meaning related with the fiber?matrix bond slip mechanism. Differently to previousprocedures in the literature, addressed to model fiber reinforced composites, where this equation hasbeen added as an additional independent ingredient of the methodology, in the present approach it arisesas a natural result derived from the multifield theory.Every component of the composite is defined with a specific free energy and constitutive relation. Themixture theory is adopted to define the overall free energy of the composite, which is assumed to behomogeneously constituted, in the sense that every infinitesimal volume is occupied by all the componentsin a proportion given by the corresponding volume fraction.The numerical model is assessed by means of a selected set of experiments that prove the viability ofthe present approach.