Resolve mesh quality issues

Practice the workflow for checking element quality and resolving quality problems.

Download and extract the part files.

Open the FEM file

Open the FEM file and reset the dialog box settings.

  1. Choose File→Open and open exhaust/exhaust_fem.fem.
  2. Choose File→Preferences→User Interface and on the Dialog and Precision page, reset the dialog box memory.

Check for duplicate nodes

Detect and merge duplicate nodes in the displayed mesh.

  1. Choose Home tab→Checks and Information group→Duplicate Nodes .
  2. In the Nodes to Check group, select Displayed.
    Duplicate nodes are highlighted in the graphics window.
  3. Click Merge Nodes to merge a parent node to any child nodes.
  4. Click Close.

Check the element normal orientation

Display and adjust the normal directions of 2D elements in the mesh.

  1. Choose Home tab→Checks and Information group→2D Element Normals .
  2. Select the 2D mesh in the graphics window.
  3. Click Display Normals.
  4. Click Reverse Normals to make the normals point outward.
  5. Click Close.

Check elements quality

Run a quality check to identify and report failed and warning elements.

  1. Choose Home tab→Checks and Information group→Element Quality .
  2. In Elements to Check, select Displayed.
  3. In the Output Settings group, from the Report list, choose Failed and Warning
  4. Click Check Elements.
    The software displays a list of failed and warning elements in a log file. In the graphics window, the failed elements are displayed in red, and the warning elements are displayed in yellow.
  5. Examine the report.
  6. Close the Log File and the Element Quality dialog box.
  7. Double-click the graphics window to refresh the display.

Set up a persistent element display

Enable display of element quality results directly in the model view.

  1. Choose Home tab→Tools group→Model Display Preferences.
  2. On the Model Colors page, set Color Basis to Element Quality Checks.
  3. Click OK. Failed elements appear in red; valid elements in gray.
    In the graphics window, the failed elements are displayed in red, and valid elements in gray.

Repair the failed elements

Manually fix poor-quality elements using element splitting tools.

  1. Choose Nodes and Elements tab→Elements group→Split Shell .
  2. In Split Methods, select Quad to 2 Triangles.
  3. In the graphics window, select the failed element.
  4. Click Flip Split Line if necessary.
    The element should be split as shown.

  5. Click Apply.
  6. In Split Methods, select Quad to 4 Triangles.
  7. Rotate the model and select the failed element, as shown.
  8. Click OK to finish splitting.
You have completed this lab.