CUBIT™ 16.08 Release Notes

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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.

New Features in CUBIT™ 16.08

Index of New Features

Meshing

Geometry

Miscellaneous

Meshing

Remesh tet with sizing option

When remeshing a set of tets, a size option is now available to control the sizes of the generated tets. The new options for this command is shown here:

Remesh tet <id_range> ... [inflate <value>] **[size <size>]** [FIXED|free] [preview]

The following images illustrate a situation where localized tets may have a larger size than desired and remeshing with a size parameter will help reduce the element size to the desired size.

Image of remesh_tet_size1
Image of remesh_tet_size2

For more information see: Remeshing

Geometry

Automatic Reduction of Thin Volumes

With the new thin volume automatic reduction functionality, 3D volumes can be automatically reduced for shell modeling while maintaining a contiguous 2D connected set of sheet bodies. Blocks are automatically created and attributed with a computed thickness and loft factor. Additional commands allow for visual inspection of the reduction and exporting a csv file containing reduction details for input deck creation.

Reduce {Volume } Thin Auto [Sort] [Preview]

For more information see: Reduce Thin Volumes

Image of reduce_thin_auto

New support for SGM with geometry classification

When importing a model into SGM, machine learning based classification is now available. Both identification of categories and training of categories is available. For example, if a model containing bolts is loaded into SGM, one can use the following command syntax to identify bolts:

list volume with category "bolt" ids

For more information about SGM see: Importing SMG Files

Miscellaneous

Cubit RGB Colors

The color specification in CUBIT has been enhanced to allow for RGB and RGBA color specification in any command. This is an addition to being able to use color names and ids. The color choosing dialog in the graphical user interface has been enhanced to support choosing any RGB color.

The new color choosing dialog
The new color choosing dialog

The syntax of these new color specifications is:

rgb <r> <g> <b>
rgba <r> <g> <b> <a>

Accepted values range between 0.0 and 1.0. An example of using this is:

color volume 1 rgb 0.5 0.3 0.9

Using the RGBA specification can be useful when making individual surfaces transparent. The alpha value can range between 0.0 and 1.0 where 1.0 is opaque and 0.0 is transparent/invisible. To make a surface transparent, issue the command:

color surface 1 rgba 0.5 0.3 0.9 0.3

Improved Model Tree Performance

CUBIT™’s user interface model tree was slowing down some of the commands. The tree has been refactored to improve performance. The model information is now copied fewer times. The relationships between the tree items has been streamlined as well.

The tree’s overhead was cut in half when creating and merging volumes. In one user’s case of renumbering nodesets, the tree’s overhead was cut down to a tenth.

CUBIT™’s Python Interface Enhancements

  • get_solutions_for_thin_volume – Parameters updated for feature improvement
  • get_solutions_for_sheet_volume_connection – Parameters updated
  • get_2D_sheet_volumes – Get sheets associated with a thin volume
  • get_3D_thin_volume – Get the thin volume associated with a sheet

The folowing methods have been updated to handle more than just volumes:

  • get_ML_classification
  • get_ML_classifications
  • get_ML_classification_categories
  • ML_train

Defects Fixed in CUBIT™ 16.08

Ref#Description
MESH-4520[Capablity-Hex Meshing] Sweeping in Cubit when there are holes
MESH-6533User Support: Mesh files not closed by lite import?
MESH-6654Cubit Training
MESH-6711seg fault when opening a interactive window in cubit python
MESH-6739Heal multiple stl files using SGM
MESH-6737Export File > sierra – fix interaction block
MESH-6710Python script seg faults
MESH-6697Error list with large number of composites
MESH-6696GUI split curve location bug
MESH-6574Id sorting in tree alphabetically
MESH-6573Compositing slowed down by model tree?
MESH-6450Slowdown in GUI when renumbering sidesets
MESH-6340RGB color in CUBIT
MESH-3934Adjust printing of current entity selected in Cubit

Documentation Updates

The CUBIT™ 16.06 online documentation may be found here. A PDF version is 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™ 16.08 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.

Platforms Supported

CUBIT™ 16.08 supports the following Platforms:

  • Linux RedHat Enterprise 7 and 8
  • Windows 10
  • macOS 10.14+

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™ 16.08 may be downloaded from the CUBIT™ download page.

Sandia Personnel Only

CUBIT™ 16.08 may be downloaded from the CUBIT™ download page.

Windows

Download a Windows installation file and double-click to install.

MAC OS X

Download a Mac OS X disk image file. After the disk image is opened, click and drag the CUBIT™ folder to /Applications.

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>
cubitThe latest released version (16.08) of CUBIT™ deployed to the LAN.
cubit -noguiThe latest released version (16.08) with just the Command Line and graphics window
cubit -nogui -nographicsThe latest released version (16.08) with just the Command Line
cubit-16.08Version 16.08 with GUI
cubit-betaThe 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

Email: asc-approvals@sandia.gov

CUBIT™ Support Lead

Trevor Hensley
Phone: 505-284-7756
Email: cubit-help@sandia.gov

CUBIT™ Project Lead

Roshan Quadros
Sandia National Laboratories
Computational Simulation Infrastructure (org. 1543)
Phone: 505-220-9458
Email: wrquadr@sandia.gov