Contents
Description
- This example creates, saves and refines a simple 2D, two-element mesh with Bilinear Lagrange finite elements.
Basic Concepts
- After completing the Mesh module tutorials 1 and 2, you should understand that:
- Each node has one or more parameters associated with it, depending on the number of variables and the basis function type(s) chosen
- Elements are defined by specifying connections between nodes
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After completing this tutorial, you should understand:
- How to make and refine two-dimensional tensor-product finite element meshes
- Useful points to consider:
- In practice, we do not typically type in nodal coordinates for real meshes. We can import nodes and elements from a tab delimited xls file using the import/export/graph button in the node and element editors.
Step-by-step Instructions
- The following instructions will guide you in creating the 2D mesh pictured below.
Start Continuity
- Launch the Continuity Client
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On the About Continuity startup screen
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Confirm that the mesh box under Use Modules: is checked
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Create Mesh
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Select rectangular Cartesian in the Global Coordinates: pop-up menu
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Click OK to submit Coordinate Form
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Choose Lagrange Basis Function→2D→Linear-Linear with 3 integration/collocation points for Xi 1, Xi 2, and Xi 3
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Click Add
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Click OK to submit Basis Form
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Confirm that Linear-Linear Lagrange 3*3 is already selected for you under Coordinate 1, Coordinate 2, and Coordinate 3
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Use the Insert Node button in the left panel to create 5 additional nodes for a total of 6
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In the Value fields next to Coordinate 1, Coordinate 2, and Coordinate 3 enter the following (X,Y,Z) nodal coordinates:
- Node 1: (0., 0., 0.)
- Node 2: (1., 0., 0.)
- Node 3: (2., 0., 0.)
- Node 4: (0., 1., 0.)
- Node 5: (1., 1., 0.)
- Node 6: (2., 1., 0.)
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Click OK to submit Node Form
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The element definition for element 1 is 1, 2, 4, 5, so enter this in the Global Node Numbers box
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Use the Insert Element button in the left panel to create another element
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The element definition for element 2 is 2, 3, 5, 6, so enter this in the Global Node Numbers box
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Click OK to submit Element Form
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Render the Mesh
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Click the lines radio button
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Click Render to display mesh
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Specify a filename to save the model in. The file will be saved as filename.cont6
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Refine the mesh four-fold and re-render
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Enter 4 for xi1, 4 for xi2, and 1 for xi3 under New Element per old element in
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Select the Local coordinates radio button under New nodal derivatives with respect to:
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Click OK to submit
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Click the lines radio button
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Click Render to display mesh. The result should look like the screenshot below.
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