Flanged Pipe Elbow
Sample Applications
Flanged Pipe Elbow
Crack growth analysis in a flanged pipe elbow
This analysis demonstrates a crack growing in the wall of a pipe elbow. The crack is located at a weld location at the end of one of the flange stiffeners. The initial crack is semi-circular with radius 2mm. The analysis is controlled by a constant amplitude applied displacement on the face of one the flanges. The face of the other flange is fixed.
The model uses the "large crack-block" approach in Zencrack. In the uncracked mesh a region of four large elements is created and tied to the surounding tet mesh. This is the blue region in Figures 2 and 3. The large crack-blocks replace these four elements to introduce the initial defect into the model as shown in Figures 4, 5 and 6.
The triangular stiffener is attached to the crack region by a tied surface. This allows the crack region to be remeshed as the crack advances. The animations in Figures 7 to 10 and the profiles in Figure 11 show that the crack grows turns and grows below the stiffener.
Figure 1 - Intact model
Figure 2 - Uncracked mesh of the model
Figure 3 - Close-up of the uncracked mesh
Figure 4 - Close-up of the initial cracked mesh
Figure 5 - Close-up of the initial cracked mesh
Figure 6 - Cut view showing the initial crack
Figure 11 - Crack profiles shown in the Zencrack GUI
Figure 12 - Ki vs crack growth at 0.5 parametric distance along the crack fronts
Figure 13 - Crack growth vs cycles at 0.5 parametric distance along the crack fronts