Damage models

Implemented methods and example 'Reinforced concrete corbel'.

InfoCAD provides the De Vree and Mazars damage models as well as a combined elasto-plastic damage model (Lubliner, Lee & Fenves).

Uniaxial stress-strain diagram according to Mazars
Uniaxial stress-strain diagram according to Mazars

Recalculation of the experiment by Mehmel & Freitag

Based on the experimental test series by Mehmel and Freitag ('Der Bauingenieur', 1967),  the illustrated reinforced concrete corbel is recalculated by using the damage models implemented in InfoCAD.

The modeling was done using tetrahedral solid elements and bar elements for the reinforcement arrangement.

The material parameters were selected based on the publication by Mehmel and Freitag.

The arc length method was used as the calculation method. The load was applied as 'displacement-controlled'.

The above figure illustrates the crack paths documented photographically during the experiment.

Comparable to the crack patterns observed during the experiment, the numerically determined damage distributions are shown above.

The crack propagation associated with the load increase causes a corresponding increase in stresses in the reinforcing bars in the damage-relevant areas of the structure.

Experimentally determined breaking load (93.3 t) and numerically calculated load-displacement curves

With all three damage models implemented in InfoCAD, the failure load determined during the experiment is predicted very well. While a breaking load of PBr=93.3 tons was determined during the experiment, values between 883 kN and 962 kN are calculated numerically (depending on the damage model and discretization). A comparison of load-deformation curves cannot be made because the load history was not documented during the experiments. Therefore, simulation results from four different publications are used as reference solutions.