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CUBIT Toolkit

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CUBIT 14.1 Release Notes

CUBIT 14.0 Logo
 

Product Description

New Features CUBIT 14.1

CUBIT 14.1 Documentation

Product Highlights

Limitations CUBIT 14.1

CUBIT 14.1 Contents of Release

Contact Information

Defects Fixed CUBIT 14.1

Platforms Supported

 

Known Defects CUBIT 14.1



 

Product Description

CUBIT is a full-featured software toolkit for robust generation of two- and three-dimensional finite element meshes (grids) and geometry preparation. Its main goal is to reduce the time to generate meshes, particularly large hex meshes of complicated, interlocking assemblies.

 

Product Highlights

Meshing: CUBIT is a solid-modeler based preprocessor that meshes volumes and surfaces for finite element analysis. Mesh generation algorithms include quadrilateral and triangular paving, 2D and 3D mapping, hex sweeping and multi-sweeping, tet meshing, and various special purpose primitives. CUBIT contains many algorithms for controlling and automating much of the meshing process, such as automatic scheme selection, interval matching, sweep grouping and sweep verification, and also includes state-of-the-art smoothing algorithms.


Geometry Preparation: One of CUBIT's strengths is its ability to import and mesh geometry from a variety of CAD packages. CUBIT currently integrates the ACIS and Catia geometry kernels directly within its code base, allowing direct manipulation of the native CAD geometry format within CUBIT. This reduces the errors and anomalies so often associated with geometry translation. CGM (Common Geometry Module) also boasts a facet-based geometry kernel developed at Sandia that can be used for remeshing or editing old mesh files or models defined by triangle facets. In addition, CUBIT has developed a comprehensive virtual geometry capability that permits local composites and partitions to geometry without modifying the underlying native geometry representation. The user can choose to ignore, clean-up or add features to the model allowing greater flexibility to meshing algorithms to generate better quality elements.


CUBIT Environment: CUBIT has developed both a convenient command line interface with an extensive command language as well as a polished graphical user interface environment. The GUI is based upon the cross-platform standard QT, which allows the same look and feel on all supported platforms. Also included is a graphical environment based upon the VTK graphics standard which has been optimized for display and manipulation of finite element data and geometry. Fast, interactive manipulation of the model is a tremendous advantage for models with thousands of parts or millions of elements.


For more information on CUBIT, including licensing arrangements and terms see the CUBIT website http://cubit.sandia.gov

 

New Features in CUBIT 14.1

Index of New Features

 

Meshing

 

'N' Tets Through the Thickness Refinement

Refine Tet Edge Command

Command for Querying Number of Tets Through Thickness

Controling gradation/growth factor in tetmesh scheme

Vertex Sizing and Automatic Curve Biasing

 

Geometry

 

Imprint Tolerant Tolerance Parameter

Merge Surface Tolerance Parameter

Align Command Enhancements

 

Import/Export

 

Sphere Element Exodus Import

Improved Patran Import

Patran file type in export dialog

 

Graphics, Utilities, etc.

 

Windows 8 Support

"Finished Command"

Mesh Quality Command Panels

New APREPRO functions

 



Meshing



'N' Tets Through the Thickness Refinement


    Cubit now provides a refinement algorithm for enforcing a minimum number of tets through the thickness of thin regions. The command for doing this is:

      Refine min_through_thickness <val> source {surface|node|tri|nodeset|sideset|block} <id_range> target {surface|node|tri|nodeset|sideset|block} <id_range> [anisotropic] [single_iteration] [dont_fill_in_gaps]


    Below is an example using the following commands:

    refine min_through_thickness 4 source surf 1 target surf 2 anisotropic

    refine min_through_thickness 4 source surf 7 target surf 13 3 14 anisotropic


    Surfaces 1 and 2 are the two surfaces on opposite sides of the thin region in the green volume and surfaces 7 13 3 14 are the surfaces on opposite sides of the thin region in the yellow volume.


    Before N through the thickness refinement.



    After N through the thickness refinement.

     

    Refine Tet Edge Command


      Cubit now provides a command to refine a single edge in a tet mesh. The command syntax is:

        Refine tet_edge node <node1_id> <node2_id>

     

Command for Querying Number of Tets Through Thickness


    Cubit now provides a command for querying the number of tets through the thickness. The command syntax is:

      Quality Surface <surf1_id> <surf2_id> num_thru_thickness

 

Controlling the gradation of mesh size with the tetmesh scheme

 

The Tetmesh growth_factor command controls the mesh gradation inside the volume. A value of 1.0 indicates a uniform mesh size throughout the volume, while values greater than 1 will grow the mesh size. In previous versions of of Cubit the growth factor had a default value of 1.05, causing the mesh size to increase slightly towards the interior of the volume. The default value for tet mesh growth ratio factor in version 14.1 is now 1.0. The new command for controlling the growth factor is as follows:

 

Volume <id_range> Tetmesh growth_factor <value 1.0 to 10.0 = 1.0>

 

 

Vertex Sizing and Automatic Curve Biasing

 

Sizes can now be specified on vertices to control biasing along curves. If a curve has a bias scheme, the vertex sizes will be honored and bias spacing will be calculated automatically for nodes along the curve. Sizes on vertices can now be set with:

 

vertex <id> size <size>

 

and bias can be turned on with:

 

curve <id> scheme bias

 

For tri/tet meshing, curve biasing is on by default to generate higher quality tri/tet meshes. Not only is the difference noticeable when setting sizes on vertices, but it is also noticeable when setting various sizes on connected curves, surfaces or volumes. To turn it off, you can issue curve <id> scheme equal.

 

sizing before sizing after

The figures illustrate the effect of applying sizes to entities. The first image shows the mesh as it would have been generated in cubit14.0. The second image shows the mesh as generated in cubit 14.1. A smoother transition is observed where a bias has been automatically applied on the side curves to facilitate the transition.


Geometry


Imprint Tolerant Tolerance Parameter


    The tolerant imprint commands now contain a 'tolerance' parameter allowing the user to specify the tolerance of the imprint operation on the fly instead of setting it globally, before issuing the imprint commmand. The commands now are:


    Surface <surface_id_range> Imprint Tolerant {Body|Volume} <range> [tolerance <value>]
    Imprint Tolerant Surface <id> [with] Curve <range> [merge] [tolerance <value>]
    Imprint Tolerant Surface <id> <id> [with] Curve <id_range> [tolerance <value>]
    Imprint Tolerant Surface <id> <id> [tolerance <value>]


Merge Surface Tolerance Parameter


    Allows the user to specify a tolerance on the fly when merging two surfces. The command now is:


    Surface <surface_id_range> Merge {Surface|Curve|Vertex} <id> with {Surface|Curve|Vertex} [Force] [group_results] [tolerance <value>]

     

Align Command Enhancements


    All the align commands now support the 'include_mesh' and 'preview' options. The former allows additional entities, merged with the source entity, to be included in the align operation. The latter allows the user to preview the align operation.

     

    Align Volume <id> Surface <surface_id> with Surface <surface_id> [include_merged] [preview]

    Align Volume <id> {Surface <surface_id>| Vertex <vertex_id>} {{X|Y|Z Axis}|{XY|XZ|YZ plane}} [include_merged] [preview]


    Also, a new align command (below) was added to Cubit 14.1. It is a rotational align, where the specified entites are rotated about the specified axis, where the angle of rotation is the angle between the first and second locations with respect to the axis.


      Align Volume <id> Location {options} with Location {options} about Axis {options} [include_merged] [preview]



Import/Export

 

Sphere Element Exodus Import


    In prior versions of Cubit, any block containing sphere elements encountered while importing an Exodus file were ignored by Cubit import. Starting in Cubit 14.1, sphere elements in exodus files will be imported into Cubit. The sphere elements can then be modified or deleted, or additional sphere elements can be created while in Cubit. During Exodus export, any blocks of sphere elements will get exported. Users can interact with the sphere elements in Cubit with the following commands:

     

    list sphere <id_range>
    list sphere ids
    draw sphere <id_range>
    highlight sphere <id_range>
    locate sphere <id_range>
    zoom sphere <id_range>


    Additional sphere elements are created in Cubit by inserting either nodes or vertices into a block with the following command

     

    Block <id_range> {node|vertex} <id_range>


Improved Patran import

 

Two new enhancements were made to improve Cubit's capability for importing and managing meshes from Patran. These include the ability to import material data from the Patran file as well as an improvement to how block IDs are assigned. Where previously a single block with an id of 0 was assigned, it now reads all blocks with appropriate ID assignments.

 

Patran file type in export dialog

 

The Patran file type .neu is now used instead of .ntr. This change affects the export dialog and the file types selected for export.

 




Graphics, Utilities, etc.

 

Windows 8 Support

 

Cubit will now run on platforms running the Windows 8 operating system

 

"Finished Command"

 

Following each Cubit command, the words "Journalled Command:..." are displayed indicating the specific command syntax that was journalled. This wording has now been changed to "Finished Command:..."

 

 

Mesh Quality Checks Command Panel

 

The following unsupported items were removed from the Mesh Quality Command panels.
Model Edge Check: Removed from Mesh->Curve, Mesh->Edge, and Exodus->Nodeset.
Topology Check: Removed from Mesh->Edge.
Coincident Quad Check: Removed from Mesh->Tet, Tri, Edge, Node, and Exodus->Nodeset.
Coincident Tri Chec:. Removed from Mesh->Hex, Quad, Edge, Node, and Exodus->Nodeset.


 

New APREPRO Functions


    Geometry and Mesh Centroid Functions:


    GeomCentroid_X("type", id)

    GeomCentroid_Y("type", id)

    GeomCentroid_Z("type", id)


    These functions calculate the geometry centroid coordinates. "type" can be "volume" or "group". If "volume", it calculates the centroid for the volume with the given id (single volume). If "group", it must be a group of volumes and it will calculate the combined centroid for the whole group with the given id.


    MeshCentroid_X("type", id)

    MeshCentroid_Y("type", id)

    MeshCentroid_Z("type", id)


    These functions calculate the mesh centroid coordinates. "type": can be "volume", "block", or "group". If "volume", it calculates the centroid of the 3D elements in the volume with the given id. If "block", it calculates the centroid of the elements in the block with the given id. If "group", it must be a group of volumes and it calculates the centroid of the group with the given id.


    Bounding Box Functions:


    BBox_XMin("type", id)

    BBox_YMin("type", id)

    BBox_ZMin("type", id)

    BBox_XMax("type", id)

    BBox_YMax("type", id)

    BBox_ZMax("type", id)


    These functions calculate the bounding box extent coordinates. "type" can be "volume", "surface", "curve", "vertex", or "group". If "volume", "surface", "curve", or "vertex" it will calculate the bounding box for the entity with the given id. If "group" it will calculate the combined bounding box for the group. A group can have any of the geometry types (vol, surf, curve, vert) in it and can be of mixed types.


    Nearest Node Function:


    NodeAt(x, y, z)


    Returns the id of the node closest to the xyz location.


Limitations in CUBIT 14.1


No known limitations.  


Fixed Defects in CUBIT 14.1


The following items are the user-reported bugs fixed since last release of CUBIT. For more information contact Byron Hanks (bwhanks@sandia.gov).


Ref #

Resolved Defect*

9675

Cubit crashes when selecting a node

9653

Stl export crashing when names exceed 64 characters

9613

Block attributes are ignored when importing a mesh

9594

Complex MBG model hangs Cubit

9585

New volume gets old id

9557

Sideset not being read in correctly

9522

Merge hangs

9513

Crash when compositing surfaces

9472

Crash in ACIS chop operation

  If a user created a custom button with no journal commands, Cubit would crash when the user pressed the custom button.
  Fixed crash when a mesh preview is done on a point curve before actual meshing.
  Fixed topology checks for blocks and sidesets. If you created a block or sideset using a volume or surface, the topology checks for model edge, coincident nodes, coincident quads, and coincident tris would fail with an error.
  Fixed imprint with zero length curve that caused crash.
  Fixed saving of tris in sidesets in a cub file.
  Fixed performance problem when reading STEP files, or any file where there are many names. This also speeds up operations where name attributes are being propagated, such as merging.
  Fixed orientation of CubitFaces when importing sidesets.
  Fixed labels drawn wrong with multiple entity types.

 

*The defects listed above are only those user-reported issues deemed "critical" or "blocker". For information on other resolved defects contact Byron Hanks.

 

Known Defects in CUBIT 14.1


The following items are bugs or limitations that may be encountered in the current release of CUBIT. For more information on these defects or to report additional defects contact Byron Hanks (bwhanks@sandia.gov).


Ref #

Known Defects in CUBIT 14.1*

Description

Suggested Work-around

N/A N/A N/A N/A

*The defects listed above are only those user-reported issues deemed "critical" or "blocker". For information on other known defects contact Byron Hanks.

 

Documentation Updates


The CUBIT 14.1 online documentation may be found here. Both a PDF version and a Microsoft Word version are also available for download. The CUBIT GUI installation also includes the full user documentation included with the program. The user's manual may be accessed from the Help menu.

CUBIT 14.1 Contents of Release


CUBIT Program
: The installation package includes executables and libraries, packaged in tar.gz files for Linux machines. For Windows, the package is in a self-installing executable, and for Mac OS X a .dmg file is provided. Both a command line and GUI version of CUBIT are included with the installation package for all platforms.


Documentation: Linux, Windows and Mac versions include full online documentation. Windows also includes .chm (Windows Help File), of the complete documentation that can be run separately from CUBIT.


 

Platforms Supported


CUBIT 14.1 supports the following Platforms:


  • Linux RedHat Enterprise 5, 32- and 64-bit

  • Windows 7, XP, Vista, 32- and 64-bit

  • Mac OS X Intel based (10.4-7)


Non-Sandia Users

CUBIT is freely available for United States government use. For more information on licensing CUBIT, including academic, commercial, and all other use, go to our licensing page. For current CUBIT users, CUBIT 14.1 may be downloaded from the CUBIT download page.

Sandia Personnel Only

Windows
In the dropzone directory \\dropzone\public\cubit\Win32 or \\dropzone\public\cubit\Win64 you may download a Windows installation file. Either copy the file for the version you require to your hard drive then double-click to install, or simply double-click on the file in the dropzone.
MAC OS X
Download a Mac OS X disk image file from the dropzone. Go to the following directory \\dropzone\public\cubit\Mac32. Copy the file Cubit-14.1-Mac32.dmg.gz to your Mac harddrive. Use gunzip to unpack the disk image file.
LINUX LANS
Check with your local LAN administrator for instructions on how to access CUBIT on your local LAN. In most cases typing one of the following commands at the UNIX prompt should allow you to execute CUBIT.  In some cases, the full path will need to be specified:
/projects/cubit/<cubit_command>

cubit

The latest released 64-bit version (14.1) of CUBIT deployed to the LAN.

cubit32

The latest released 32-bit version (14.1) of CUBIT deployed to the LAN

cubit -nogui

The latest released 64-bit version (14.1) with just the Command Line and graphics window

cubit -nogui -nographics

The latest released 64-bit version (14.1) with just the Command Line

cubit-14.1

64-bit Version 14.1 with GUI

cubit32-14.1

32-bit Version 14.1 with GUI

cubit-beta

The latest beta version still in development

 

Contact Information


CUBIT Help

For general technical questions including download, installation and CUBIT technical assistance.
cubit-help@sandia.gov

CUBIT Licensing and Passwords

Charis Church
Cubit Licensing
Phone: 505-284-6464
Email: cchurch@sandia.gov

CUBIT Support Lead

Bob Kerr
Cubit Support Lead
Phone: 505-844-8606
Email: cubit-support@sandia.gov

CUBIT Project Lead

Byron Hanks
Sandia National Laboratories
Computational Simulation Infrastructure (org. 1543)
Phone: 505-845-0500
Email: bwhanks@sandia.gov

Web site contact: Cubit Support