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Quick TetraMesh

Quick TetraMesh

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Quick TetraMesh

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The Quick TetraMesh macro quickly creates a tetramesh of an enclosed volume defined by geometry and/or elements. Its main objective is to quickly and automatically create a tetramesh that meets the minimum interior angle and minimum element size. During the process of quick tetramesh, the mesh may deviate from the underlying geometry in order to maintain good quality elements. To alleviate this, you can select Sacred elements so that the tetmeshing function closely follows the original geometry. This macro is accessed on the Geom/Mesh Utility menu located on the standard Utility menu, and displays in a new tab in the tab area.

quick_tetramesh

The following options are available in the Quick TetraMesh macro:

Option

Description

Volume complist

Double-click components and use the comps collector that displays in the panel area to select comps representing the geometry of the solid to be tetra meshed. Surfaces and/or elements can be used to define the volume. Click proceed to finalize the selection.

Minimum tria angle

The surface trias from which the tetramesh will be extrapolated will be generated with angles that measure at least this many degrees. Use this control to limit how acute the resulting elements will be.

Maximum feature angle

The maximum feature angle protects nodes on corners with a feature angle greater than the value specified, helping to better maintain the geometry. This applies only to cases where you can maintain features while fixing minimum element size. For example, if two nodes of an element share different features (as in thin steps), the features may not be maintained as they do not pass minimum element criteria.

Maximum reverse angle

The maximum feature angle allowed between normals of adjacent elements.  If the feature angle exceeds the given value, two adjacent elements are considered reversed and actions are performed to correct the situation.

Mesh size

Average element size of the mesh to be created.

Minimum edge size

No single edge of any generated element will be shorter than this.

Minimum elem size

Minimum allowable area for any element.

Sacred surface

When element nodes are moved to improved element quality, it gives special preference to trying to keep the nodes on a sacred surface.

Note:This does not work if two adjacent surfaces are both marked as sacred.

Sacred elements

These are existing trias that you have created according to your requirements and wish to maintain while tetrameshing the part. This is useful in ensuring that a particular feature is captured exactly the way you want it to be. The tetramesher will not move the nodes of these elements, even if doing so would improve element quality.

Note:This setting overrides the float setting in the tet from option, but only for the elements selected as sacred.

Mesh type

The mesh type options are Trias Only and Mixed.  With the Mixed mesh type, both trias and quads may be created.

Mesh density

Choose between chordal deviation and uniform. Chordal deviation uses smaller elements along curves, feature lines, and edges to improve accuracy, but requires more computing time. Uniform uses identically-sized elements throughout the mesh, but may produce low-quality elements along such locations.

Tet from

Choose floating, in which the quick tetramesher is free to move nodes in a surface tria mesh to achieve better tetra elements based on them, or fixed, in which the mesher must keep the tria mesh unchanged.

Mesher

Choose between automesh and batch. This determines the meshing engine used: the one used by the Automesh panel, or the one used by the BatchMesher. The BatchMesher generally produces better results, but does not currently support sacred surfaces or elements, ignores/replaces existing elements, and always uses uniform density.

Perform mesh
cleanup only

When this option is checked, no tetra elements are created and the macro simply goes through the cleanup steps for the shell mesh. Some of the cleanup operations performed are: the suppression of free edges, correction of sliver elements, splitting of elements, and projections onto the original geometry. All the cleanup steps are designed to improve the mesh quality.

Mesh

Perform the quick tetramesh with the specified settings.

Note:There is no Undo function. You can, however, attempt to remesh using different settings if you do not like the initial results.

Debug Surface Mesh

A series of tools that help you locate problem areas which can cause poor meshing:

Find Holes

Locate holes in your model.

Find T-Con

Locate T-connections in the model.

Dihedrals

Locate features in the model that have feature angles greater than 150 degrees.

Attached

Locate entities attached to the selected components.

Try TetraMesh

After making adjustments, click this to re-run the meshing operation on the same components.

Help

Opens a pop-up window with basic information about each control that displays on the tab.

Close

Closes the tab.

The Quick Tetramesh macro meshes the unmeshed surfaces in the model using chordal deviation and fixes all the elements that fail the criteria provided. You can manually mesh some critical geometry and select those elements as sacred elements. These sacred elements need to be trias.  As a part of the cleanup, the tool heals small cracks in the model.

Suggested process to effectively use quick tetramesh:

1.Load the geometry.
2.For critical areas where you want to control the mesh such as bolt holes, manually mesh using chordal deviation.  Select these elements as sacred elements.  This helps to obtain the desired mesh in critical areas.
3.Launch the Quick Tetramesh macro.  Run with the desired mesh size.
4.Identify problem areas, if any (for example any surface edges that were ignored, or if mesh in certain areas is not satisfactory).
5.Use the Delete panel to delete the tetras, then manually mesh problem areas.
6.Re-launch the Quick Tetramesh macro and select sacred elements to protect.