A quasi-isotropic continuum damage model for concrete with strain decomposition

It is proposed a new model for materials characterised by cohesive fracture, as concrete and fibre-reinforced mortar is presented based on Continuum Damage Mechanics. It includes the effects of fracture evolution, void compaction, micro-fracture coalescence, modelled by means of different types of internal variables. The different response under tensile and compressive stress states is accounted for introducing two damage variable, that evolve independently. The model is defined by the specification of the internal energy and dissipation functionals, based on few material parameters of easy physical identification. Two forms for the internal energy are examined in the paper, each using a different separating condition between the tensile and the compressive regime, performed in such a way that no discontinuity appears in the stress-strain law.

concrete, cohesive fracture, Continuum Damage Model, strain decomposition.