1. Reference problem#
1.1. Geometry#
We consider a parallelepiped of size \(30\mathrm{\times }30\mathrm{\times }10\mathit{mm}\) which has three holes and a crack on one of its sides (figure).

Figure 1.1-a : geometry of the structure under consideration
1.2. Material properties#
No material is defined because we cannot solve the finite element model in a step.
1.3. Boundary conditions and loads#
No boundary conditions are defined because we do not solve the finite element model: we will calculate two propagations in mode I of the existing crack with imposed and constant displacement along the bottom. The crack remains flat during propagation.
At each propagation step, an advance equal to \(\Delta a\mathrm{=}12\mathit{mm}\) is imposed. The bottom of the crack spreads while always staying straight.
1.4. Initial conditions#
The initial crack is a half-plane. Its length is equal to \({a}_{0}\mathrm{=}4\mathit{mm}\). The bottom of the crack is straight.