GGU-ELASTIC: Step 2: System input

The problem is symmetrical, so we need only consider one half. We will choose the right half. The coordinate system should be selected such that the foundation centre is at x = 0.0 m. The foundation base has a y-value of 10.0 m.

The system can be described with a few distinctive points, so input can be carried out easily using a table. Select the menu item "FEM mesh/Change (nodes)" and then the "Via a table" button. Change the number of nodes to 7 and enter the values from the following dialog box.

In principle, 5 points would have been sufficient to describe the system:

• four corner points

• right foundation edge

However, two additional points have been added in order to get a slightly tighter mesh in the foundation area.

Select the menu item "FEM mesh/Automatic". The program connects the seven points to a FEM mesh. Then go to the menu item "Page size + margins/Auto-resize" or click the [F9] function key to get a screen-filling system presentation.

Select the menu item "FEM mesh/(Refine) All" and press button "3".

Repeat the mesh refinement. You should now have a system with 96 triangles and 61 nodes. The current numbers are displayed in "System/Info".

Now select the menu item "FEM mesh/Optimise".

Press the "Topology" button to get a numerically favourable mesh.