Release Notes for Coreform Cubit 2021.11

Usplines

U-splines are a revolutionary new spline technology, developed by Coreform, and can be thought of as a generalization of B-splines, NURBS, and T-splines. A U-spline is created by first generating a linear mesh to define the spline’s topology, then prescribing the polynomial degrees of the elements and degree of smoothness with their neighboring elements, and finally computing the resulting U-spline in Coreform Cubit. The generated U-spline can then serve as a watertight CAD geometry definition and can be used as an accurate and computationally efficient mesh for simulation, a technique known as isogeometric analysis (IGA).

Usplines: Initial support in ANSYS LS-Dyna

Bézier Extraction is an IGA/spline technology that transforms a spline into a traditional “element point of view” format that can be more readily implemented in traditional finite element codes. ANSYS LS-Dyna supports Bézier extraction via DYNA’s *IGA_INCLUDE_BEZIER keyword and the “BEXT” files that Coreform Cubit can export from a U-spline.

Geometry Compliant Lattice Structures

Geometry Compliant Lattice Structures (GCLS) is a novel lattice construction technology that enables the efficient design of lattices that conform to a CAD model’s shape and size. GCLS structures are built using a background U-spline mesh, which the user generates on a CAD volume of the lattice region. Several default lattice unit cells are provided, as is a workflow for designing custom unit cells. This new capability is available as a separately-licensed product, Coreform Lattice GC™ . Contact sales@coreform.com for a free trial or other inquiries.

Updates to Coreform Cubit Learn licensing

We at Coreform are committed to ensuring that students, hobbyists, and open-source simulation developers have access to the world-class mesh generation capabilities in Coreform Cubit. In the 2020.2 release we accomplished this by releasing the Learn license for Coreform Cubit. Beginning with Coreform Cubit 2021.11, we have streamlined the licensing process for Coreform Cubit Learn. Going forward, all Cubit Learn licenses will require internet access and an account at coreform.com to be activated. All legacy Coreform Cubit Learn licenses that used the RLM server will expire 60 days following the release of Coreform Cubit 2021.11 (approximately January 2022).

All Coreform Cubit Learn users are invited to obtain a new Coreform Cubit Learn license by following this process:

1. Get the new Coreform Cubit Learn license:

2. Download the latest version of Coreform Cubit:

3. Activate new Coreform Cubit Learn license:

Changing tool for generating documentation

For many years Cubit’s help content has been generated using Adobe’s RoboHelp software. We’re transferring to using Scribble as our documentation tool, which is based on the Racket programming language. This transfer of documentation tooling, while still in its infancy, is now “live.” We expect there to be some rough edges, so if you find any issues with the documentation please send us a bug report at support@coreform.com!

Geometry tools: Taper surfaces

Exposed ACIS “taper” operation that tapers an array of faces about an array of corresponding edges and a supplied draft direction by a given draft angle.

Geometry tools: Create tangent curve

Added a new curve construction method that creates a spline curve that connects two points with prescribed tangent direction at each point. This can be particularly useful for smoothly connecting two discontinuous curves.

Mesh export: ’mesh-only’ export for ANSYS LS-Dyna

A new option has been added to the LS-DYNA .k mesh export utility to enable only writing the mesh data, which can then be *INCLUDE-ed into another LS-DYNA .k file. Previously, this exporter would output a minimum working input file that included “dummy” keywords for items such as materials, steps, etc.

User experience: Improved performance importing complex assemblies

Improvements to file-reading algorithms have resulted in dramatically (>10x) faster performance when importing certain STEP files. For example the wall time required to read a large test file has been reduced from ~720 seconds to ~20 seconds, matching the performance of other, industry-leading CAD software. The specific change is a refactor of the algorithm that checks for clashing entity names, turning an algorithm into an algorithm. This is not a breaking change.

New features in Coreform Cubit 2021.11

Defects FIXED in Coreform Cubit 2021.11