Modeling the hygro-mechanical response of quasi-brittle materials

Performing accurate, large scale computations requires a model formulated on the macro-scale, but involving relevant physical phenomena taking place on the lower scales. In the present paper, a macroscopic framework for the simulation of the hygro-mechanical response of quasi-brittle porous materials is proposed. The model employs the partition of unity (PU) concept and introduces a new generic cohesive law. With the PU concept, crack growth can be studied on relatively coarse meshes. The new cohesive law allows extending most continuum models to a discontinuous framework, hereby adding the effect of macro-crack formation by the growth en coalescence of micro-defects. The capabilities of the model are illustrated by means of a simple poromechanical material model. It is shown that good correspondence with experimental results is already obtained based on linear elasticity and a perfectly brittle response. It can be expected that the use of more sophisticated material models will lead to better results.