Export vertices and elements from finite element models in the database

Description

  • This page explains how to export vertices and elements from Continuity's database to portable formats.

Register and Connect to the Database

  • You will need to download Continuity (http://continuity.ucsd.edu/Continuity/Download) and register to have access to the database.

  • Open Continuity. When the splash screen loads, click "OK".
  • To connect to the database, click "File", "Library", and "Search", as in the image below





Selecting a model from the database

  • You can scroll up and down, or do a search for a keyword in the model name at the top of the screen to find a model.
  • Here, we selected a model (in purple) called "pt68_LA_142"





  • Notice the tree widget in the bottom half of the screen. This is where you can export the vertices and elements.
  • If there is a "+" next to "Mesh". Click this "+" and a list of objects should appear underneath.

Export the Vertices

  • We refer to the vertices as "Nodes". Click "Nodes" as indicated in blue letters below.





  • A new box (the nodes form) should appear.
  • If you want to export the mesh as a linear mesh (i.e., not a cubic Hermite mesh), change the basis functions as indicated by clicking the drop-down menu and changing the basis function from Cubic Hermite to any Linear Lagrange basis (blue highlight) for all three columns: Coordinate 1, Coordinate 2, and Coordinate 3. Even if you want to export a cubic Hermite mesh, you should still probably export as a linear mesh for simplicity, as the derivative information is also present in the "Scale Factors Form".





  • Next, click the button "Import/Export/Graph" along the bottom-left. A table will appear with the information.
  • Click "File", and then "Save", as highlighted in the image below.





  • An Explorer should pop-up, and you will be prompted to save the file. You can save as a ".txt" or ".xls" extension.

Export the elements

  • Back at the database screen, under the heading "Mesh", there should be a subheading "Elements", as indicated below. Click "Elements".



  • A box (the elements form) should pop-up. It looks like the picture below.
  • Click "Import/Export/Graph"



  • Another form will pop-up to allow you to export the elements. It appears below.



  • When the Explorer pops up, name your file with the extension ".txt" or ".xls"
  • The ordering of the four (eight) vertex numbers listed for each quad (hex) adopt a convention to indicate how the vertices are connected. You may refer to the documentation below to see the convention. (Many geometric modeling softwares use a clockwise or counter-clockwise ordering convention, which we do not use because it is less logical in the context of finite elements.)