Assignment around points

  1. Select Meshing Assign sizes Points. A window comes up in which to enter the element size around the points to be chosen. Enter 0,1 and click OK.
  2. Select the point indicated in Figure 3. Press ESC to indicate that the selection of points is finished.
  3. Select Meshing Generate.
  4. A window comes up asking whether the previous mesh should be eliminated. Click Yes.
  5. GiD then asks you to enter the maximum element size. Leave the default value unaltered and click OK.
  6. Figura 3. Geometry of the model. The point around which the mesh will be concentrated.

     

    Figura 4. The mesh with a concentration of elements around the point.

  7. A concentration of elements appears around the chosen point, given the selected size (0.1) of these elements. (See Figure 4)
  8. Go to Utilities and open Preferences. Click Meshing. In the window that appears there is an option Unstructured Size Transitions. This option defines the transition gradient of element sizes (size gradient), the gradient values being between 0 and 1. The greater the size gradient, the greater the change in space. To test this, enter the value 0,8 and click Accept.
  9. Again, select Meshing Generate.
  10.  

    Figure 5. Mesh with the elements concentrated
    around a point, with a size gradient of 0,8.

     

  11. The size gradient (0,8) results in a lower density around the point. Nevertheless, those elements with a maximum size of 0,1 are very concentrated. (See Figure 5.)
  12. Now go back and enter 0,4 in Unstructured Size Transitions. This will result in a mesh more suitable for our objectives. Click Accept.