Phase‐field modeling for failure behavior of reinforced ultra‐high performance concrete at low cycle fatigue

Abstract The influence of different fiber contents and orientations on the overall material behavior of steel microfiber reinforced UHPC is studied. To analyze the failure behavior of UHPC, the three‐point bending beam tests at low cycle is investigated experimentally and simulated numerically. For that purpose, recently developed phenomenological material model, see our recent works [1] and [2], based on the combination of elasto‐plastic phase‐field model for fracture and transversal isotropic elasto‐plasticity is implemented. For the modeling of distinct behavior of UHPC in tension and in compression, two different continuous stepwise linearly approximated degradation functions are used, cf. [3]. The numerical calibration is done using the measured mechanical properties of UHPC and steel fibers in the experiments. To use the different fiber distributions and orientations of steel fibers, the orientation distribution functions (ODF) are constructed. The prediction capability of the presented numerical model in terms of accuracy of numerical results comparing to the experimental data is discussed.