Numerical prognoses of durability of structures made of cementitious materials such as concrete requires the consideration of environmental loads in addition to external loading [
]. For problems such as cracking of concrete structures, joints in rocks or shear bands in soft soils, the moisture transport in the opening discontinuities has to be taken into account in durability oriented analyses. The paper is concerned with a concept for coupled hygro-mechanical analyses considering discontinuities in the context of the extended finite element method [
]. The spatial discretization of the displacement field as well as the moisture field, represented by the fluid pressure, are additively decomposed into a regular part and an enhanced part representing possible jumps in the primary variable. The extension to hygromechanical couplings involves the consideration of jump conditions across discontinuities as well as fluid transport in the intact part and the discontinuity, respectively. The present formulation is restricted to fully saturated conditions. The coupled model is investigated by means of an academic benchmark example, characterized by an artificially introduced crack, is analyzed numerically considering a hygromechanical loading scenario.
An additional aspect addressed in the paper is concerned with the evaluation of different crack propagation criteria for the determination of the crack growth direction in cementitious materials. A benchmark example characterized by Mixed-Mode fracture is presented to study the performance and robustness of these criteria.