CUBIT 13.1 Release Notes
Contents
1. Curve Orient Sense Command Selecting a solution will show the volume that the overlap region will be subtracted from and clicking Execute will do the subtraction The tangent direction or orientation sense of one or more curves can now be modified using the new command curve orient sense Orientation can be defined using location and direction options This is especially useful when defining the bias characteristics for multiple curves simultaneously Sweep Sheet with Multiple Surfaces The ability to sweep or extrude a surface to generate a volume has been an important capability in Cubit however it has been limited to sweeping single surfaces Cubit 13 1 adds the capbility to sweep multiple surfaces that belong to the same sheet body in the same command The following figure at left shows a single sheet body containing 4 separate surfaces The result is shown at right where all 4 surfaces have been http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 7 of 14 extruded siultaneously Sweep Meshed Surfaces Cubit currently provides the capability to create a volume by sweeping a surface through a specified path With this release we provide the feature to sweep a meshed surface This means that a swept solid mesh will also be generated in the new volume based on the 2D mesh defined on the source surface To use this Capability use the new include_mesh option on most of the sweep surface2. New include merged option in Move and Rotate Commands To apply a transformation such as a translation or rotation to a set of merged bodies Cubit previously required that each of the volumes to be moved be transformed separately Cubit 13 1 introduces the new include merged option for both the rotate and move commands which will automatically apply the same transtormation to any entities that are merged with the specified entity Move Group Command The syntax for the command Move Vertex Curve Surface Volume B ody Group lt id_range gt has now been updated to include Groups This makes the command Move lt entity gt syntax consistent with the lt entity gt Move form of the command Scale About Reference Point Command The scale transformation in Cubit has now been enhanced to permit scaling about an arbitrary reference point rather than the previous capability of scaling about the origin Materials and Boundary Conditions http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 9 of 14 New Initial Condition Options Users may now create and modify initial conditions of temperature displacement velocity acceleration and field variable Initial conditions are applied to nodesets Presently an initial condition may apply to a single nodeset Commands to list and delete initial conditions are also available New Material Creation Options Users may specify user constants as part of a ma
3. commands The image at left shows a surface sheet body that has been meshed with quads Applying the sweep Surface command with the include_mesh option resulted in the mesh at right The result is a volume meshed with hexahedra where the mesh intervals in the sweep direction are automatically computed Sweep Meshed Curves similar to sweeping a meshed surface to create a meshed volume Cubit 13 1 also introduces the feature to sweep a meshed curve into a meshed surface The resulting mesh generated on the new surface will be a mapped mesh using the intervals defined on the source curve with automatic intervals in the sweeping direction To use this capability use the new include mesh option on the Sweep curve command New Merge Option in Split Curve Command Previously the split curve command would split a curve at a specified location but leave the two or more resulting curves unconnected The new merge option allows the user to automatically connect the two curves where the new vertex is created New Create Curve Arc Command Options Two new options for creating Arcs in Cubit have been added These include 1 Create an arc by selecting two end vertices and specifying a radius and normal direction 2 Create an arc using the center position of the arc the radius the normal direction and the sweep angle http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 8 of 14 New Options in Loft Volume Co
4. html 2012 05 21 CUBIT 13 1 Release Notes Page 12 of 14 Curve The image on the left shows a close up of the model above where a small fillet has been detected The image on the right shows the same region of the MBG model that has been defeatured In addition to the power tool a new command has been added to support this new capability Defeature volume lt id_range gt auto identify curve length lt value gt Curve lt ids gt curve_curvature lt value gt Curve lt ids gt surface_curvature lt value gt Surface lt ids gt Surface prox2d lt value gt Surface lt ids gt group lt id gt keep Also available after issuing set dev on this command provides the full functionality of the automatic defeaturing capability from the command line for use in scripts and journal files Back to New Features Limitations in CUBIT 13 1 As of Cubit 13 0 the Granite Geometry Kernel is no longer supported The Mac OS X port does not support the changing mouse cursors on pre selection It is recommended that a 3 button mouse be used for the Mac OS X version since interactive transformation utilizes all three buttons Fixed Defects in CUBIT 13 1 The following items are the user reported bugs fixed since last release of CUBIT March 2011 For more information contact Brett Clark bwclark sandia gov Resolved Defect The defects listed above are only those user reported issues deemed critical or blocker For infor
5. html 2012 05 21 CUBIT 13 1 Release Notes Page 3 of 14 Remesh Tets Parallel Refinement Deteaturing Tool Meshing Adjust Boundaries Orthogonal Command Adjust Boundaries Orthogonal is a new mesh operation that applies smoothing to the nodes of both the curves and surface simultaneously to achieve approximate perpendicular mesh edges at the boundaries These images illustrate the effect of the adjust boundaries orthogonal command Left is the initial mesh and right is the mesh after applying the command New Sweep Meshing Options Sweeping continues to be the workhorse algorithm for Cubit where a large portion of volume meshing tasks utilize this important capability A number of new options have been added for this release allowing the user greater control over the resulting hex mesh The following outlines the main new features 1 Propagate Bias The new propagate bias option attempts to preserve the source bias by propagating bias mesh schemes from the curves of the source surface to the curves of the target surface 2 Sweep Smoothing To ensure adequate mesh quality optional smoothing schemes are available to reposition the interior nodes The sweep tool permits five types of smoothing linear smart affine residual winslow and auto These smoothing schemes are described in more detail in the documentation 3 Sweep Transform Swept meshes are created by projecting points between the source and target Surfaces usin
6. CUBIT 13 1 Release Notes Page of 14 ee aiins ta lt u Seat cn OUT uu it Home Licensing Tutorials Documentation Support Downloads Links Ae SoS lt SS SS SS SS ES SNES S NS NS SE a ek 413 1 Release Notes Released October 2011 Product Description New Features CUBIT 13 1 CUBIT 13 1 Documentation Product Highlights Limitations CUBIT 13 1 CUBIT 13 1 Contents of Release Contact Information Defects Fixed CUBIT 13 1 Platforms Supported 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 vari
7. ation that can be run separately from CUBIT Platforms Supported CUBIT 13 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 available for government and academic use For information on licensing CUBIT go to the follow URL http cubit sandia gov licensing html For current CUBIT users CUBIT 13 1 may be downloaded from the website at the following URL hitp cubit sandia gov downloads html If you obtained a password since the release of CUBIT 10 0 your password should work for 13 1 also Sandia Personnel Only Windows Download a Windows installation file from the dropzone Go to the following directory dropzone public cubit Windows Copy the file Cubit WindowsGUI 13 1 exe to your windows hard drive Double click on the file and follow the installation instructions MAC OS X Download a Mac OS X disk image file from the dropzone Go to the following directory dropzone public cubit MAC OS X Copy the file Cubit GUI 13 1 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 lt cubit_command gt h
8. automaticaly detect and display small features in the model that can be automatically removed The list can be edited to add or remove features to be defeatured Individual entities can be graphically interrogated as in other power tools selecting the execute button will create a new defeatured mesh based geometry model With the current release anew model is generated using Cubit s grouping mechanism where new defeatured volumes are generated and assigned to a user specified group Meshing can then be performed on the resulting defeatured model AP Cubit 131b hosi Fie Edit Yiew Display Tools Help DSB Nw Pee Power Tools o x 3 0 MGH EEEO ECOLES a OE DEE Volume IXs al Curve 210 piia 4 _ Curve 5na Analyze m 4 j Entjes to be Defeatured ue Teo Cu rve 187 ikem Size 2 ai e Surface 94 Smal Curk Leng sue 2 ri Surf io orth Curve 164 surface 97 4Narrow SiL Are gt x ON Surfa 012500000 Urve 199 Cunete uy ae n uae 82 C wo x Surfa O00 i uriace l Cunet6 CuRe a antic oy surtae lg igh Drow Locate Char N Surtate taa apogeu a X Deleatured Group Kamm delapture group ot ees FTogesties Page a x Peto Actin lt aa ra a pa x oe The defeaturing power tool shown at the left detects and displays features that will be eliminated when the execute button is selected and a new MBG model is generated http cubit sandia gov release_notes 13 1
9. ements Cubit writes a different element file for each part Flat file Use the flatfile option to export a Abaqus file with all nodes and elements in the global space i e no PART or INSTANCE keywords New Solid Option when exporting IGES The new solid option on the export iges command allows solid volumes to be exported as Manifold Solid B Rep Objects MSBO Without this option the iges file is simply a collection of stand alone surfaces Graphics Utilities etc New Delete APREPRO variable function Users may now delete APREPRO variables after one is defined For example the following snippet defines a variable uses it in a Cubit command and then deletes it var1 2 P 1 5 create brick x varl y varl1 2 z var1 1 5 delete var1 The delete functionality has also been incorporated in to the Graphical APREPRO Editor where the ability to delete a variable after it has been defined in the table can now be performed http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 10 of 14 New Color Global Command Normally Cubit will display surfaces and curves in a rotating set of default colors The ability to assign a single designated color to all surfaces curves and vertices has been added for Cubit 13 1 Beta Features Cubit remains an active development platform for cutting edge methods in geometry preparation and mesh generation Some features that are still under develoomen
10. ety of CAD packages CUBIT currently integrates the ACIS Granite 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 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 http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 2 of 14 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 millio
11. g affine transformations and then connecting them to form hexahedra The method used to calculate the affine transformations is set using the sweep_ transform option In previous versions of Cubit a generalized least squares approximation was used for computing node locations which could sometimes perform poorly for simple translation sweeps In Cubit 13 1 we introduce an explicit translate option that will perform a simple interpolation between source and target surfaces Although least squares remains the default sweep transform method and is the most general consider using translate if you get poor result on simple linear translation swept volumes 4 Autosmooth target With this option turned on the target surface mesh is smoothed before the volume is swept rather than relying on the sweep transformation to place the nodes Coincident quad check improvement The topology check coincident quad command now checks for nodes at the same location whether they are part of the same quad or a different mesh block In other words instead of comparing only the actual nodes used to define the two quads coincident nodes on neighboring meshes are also checked The previous behavior would detect no coincident quads in two adjoining unmerged blocks Directional Refinement Often there are cases where the model dictates a very thin region such as a gasket or membrane adjacent to a large blocky region To achieve a good element aspect ratio in the thin part
12. mation on other resolved defects contact Brett Clark http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 13 of 14 Known Defects in CUBIT 13 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 Brett Clark bwclark sandia gov Known Defects in CUBIT 13 1 Suggested Work around The defects listed above are only those user reported issues deemed critical or blocker For information on other known defects contact Brett Clark Documentation Updates The CUBIT 13 1 online documentation may be found at the following URL http cubit sandia gov help version13 1 cubithelp htm 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 Helo menu CUBIT 13 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 document
13. mmand The Create Volume Loft command in Cubit provides the ability to create a volume between two or more reference surfaces The resulting volume can be controlled in a variety of ways Cubit 13 1 introduces several new keywordsto the create volume loft command to extend the control of how the resulting volume is defined These include Guide curve Takeoff factors Takeoff vector Match vertex Closed Preview and 2 Show matching curves See the documentation for a complete description of each option Surface Os 082 cons 06 These new options can be controlled through an extensive new GUI command panel a iE ghown at left It can be accessed through the command panels at Geometry gt Volume gt vex Create gt Lofted Volume Suara The images below illustrate some of the new capability The first image shows three independent surfaces that will be used as reference surfaces for the loft The second image shows a resulting lofted volume where the takeoff factors have been adjusted The third image shows the use of a guide curve where curve 49 was used to guide the loft through the three surfaces New Options in Sweep Surface Command The ability to extrude a surface to create a volume has been available in Cubit for some time now In Cubit 13 1 we introduce several new options for defining the direction of sweep These include Cartesian axes curve tangent surface normal and various methods for defining a vector
14. ns of elements For more information on CUBIT including licensing arrangements and terms see the CUBIT website http cubit sandia gov New Features in CUBIT 13 1 Index of New Features Meshing Adjust Boundaries Orthogonal Command New Sweep Meshing Options Coincident quad check improvement Directional Refinement Improved preview for curve meshing New Options in Curve Bias for Multiple Start Positions Geometry New Curve and Volume Helix Creation GUI for Midsurface Command Manage Gaps and Overlaps Tool Curve Orient Sense Comand sweep Sheet with Multiple Surfaces sweep Meshed Surfaces Sweep Meshed Curves New Merge Option in Split Curve Command New Create Curve Arc Command Options New Options in Loft Volume Command New Options in Sweep Surface Command New include merged option in Move and Rotate Commands Move Group Command Scale About Reference Point Command Materials and Boundary Conditions New Initial Condition Options New Material Creation Options New Copy Boundary Conditions Options Boundary Conditions propagated through Copy and Webcut Operations Import Export Partial ABAQUS Export Enhanced ABAQUS Export Command New Solid Option when exporting IGES Graphics Utilities etc New Delete APREPRO variable function Axis Display Settings New Color Global Command Beta Features http cubit sandia gov release_notes 13 1
15. nually done in cubit The packaged solutions allows the user to quickly step through each problem and fix it http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes W Cubiti31b File Edt View Display Tools Help DADES SMU Po SVOVIDAGIF caQgeezoggst Puer Tools fx s n i F ESE BL BR Tas _ gt a Manage Gaps ond Overtaps Lise the button below ip defect any gams or owerlans r your mode impart or Geste MaxGeo 0005 Gramer y Max Gap Ange Setup FEA 7 Auto up ate Detect Gaps and Overiaps Model h Entity D Distance By 4 Overlaps 1 odes Pair 3 1 Gene fy Vaheme 3 P Volume Mesh Valdate Dafrya Solutions BCs Pompble Solutions u Subtract overlap from Volume 1 Export Subtract overlap fram Volume 3 Mes Executes Also consider the following solubons avaliable from the Guth Cosy Panel Intersect Boolean operaen to intersect owerlagging voksmes Tweak Surface Adhat surface location to avoid overlap More Inferinaben Dons Distance Entity ID a Overlaps 1 Pair3 1 Solutions Page 6 of 14 Font aia 3 1 4 Eram 9 a gt j Right clicking on an overlap pair in the list and choosing Draw Pair will draw the two volumes with the overlap and shade the region of overlap Possible Solutions Subtract overlap from Volume 1 Subtract overlap from Velume 3 Execute
16. ommands create curve helix zaxis location 10 0 thread distance 1 angle 5000 left handed create curve helix zaxis location 10 0 thread distance 1 angle 5000 right_ handed The image on the right was created by sweeping a circle along a helix path using the following commands create surface circle radius 0 5 yplane body 1 mov x 2 Sweep surface 1 helix zaxis thread distance 3 angle 1000 right_handed http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 5 of 14 GUI for Auto Midsurface Command The ability to automatically create midsurfaces from volumes is a relatively new feature in Cubit In version 13 1 we introduce a command panel in the GUI to control its options It can be accessed trom the command panel Geometry gt Surface gt Create gt Auto Midsurface Manage Gaps and Overlaps Tool Cubit 13 1 has a new tool for quickly identifying and fixing gaps and overlaps in assembly models The Gaps and Overlaps Tool is part of Cubit s Wizard Power Tool or ITEM This tool provides diagnostic information on gaps and overlaps Cubit 13 1 introduces a smart solution interface that provides options for resolving the issues that were identified When the user selects an issue identified by Cubit the tool displays possible solutions for fixing it The user simply clicks execute to perform the selected solution Solutions usually consist of typical intersection subtraction or tweak operations that are currently ma
17. t may not be quite ready for release but may be valuable in some settings The following is a list of new beta features that have been made available in Cubit version 13 1 Their functionality is not yet complete has not been fully tested however in many settings the new capability may be very valuable Your help in reporting defects and offering suggestions on these features is appreciated To turn on or off any of the features listed below issue the following command from the command line Set developer on off Remesh Tets Free Option The remesh tet lt range gt free command is a beta feature and requires the user to enter the command set developer on to enable it The free option enables the new capability to re mesh merged and unmerged surfaces that may bound the specified range of tets A new triangle mesh replaces the old one which may improve element quality if the old mesh is distorted This option does not yet remesh curves that are within the range defined by the tets The left image shows the initial deformed tetrahedral mesh The right image shows the mesh after re meshing with the free option and an analysis based sizing function Parallel Refinement For those who have access to the Sierra stk_adapt module Cubit 13 1 supports parallel refinement Parallel mesh refinement allows refinement to go beyond the memory limits of a single processor The resulting mesh size is only limited by the number of processors you ha
18. terial definition User constants are stored as field properties The user may also specify a value for DepVar which is an Abaqus specific variable New Copy Boundary Conditions Options When creating new geometric entities using Cubit s Copy command Nodesets Sidesets and Blocks defined on the original entity can now also be copied The following commands can be used to turn this feature on and off for nodesets sidesets and blocks respectively setcopy nodeset on geometry copy on OFF use original setcopy sideset on geometry copy on OFF use original setcopy block on geometry copy on OFF use original Boundary Conditions propagated through Webcut Operations New geometric entities will also be created when using Cubit s webcut operations Nodeset Sideset and Block information contained on the original entities can now also be transferred to the resulting webcut entities Imporv E xport Partial ABAQUS Export Cubit can now export an Abaqus deck that contains only the mesh described by the NODE ELEMENT NSET ELSET and SURFACE keywords Use the partial option to get only the mesh portion of the Abaqus file A complete file also includes the Abaqus keywords and data used to define parts assemblies instances materials initial conditions and analysis parameters Enhanced ABAQUS Export Command Node file element file output Use the nodefile and elementtfile options to export separate files of nodes and el
19. the element size in the thick region would may need to be too small Directional refinement addresses this problem by allowing the user to limit the directions in which refinement will take place using a reference surface or plane These figures show how the green membrane was refined only in the plane of the membrane without adding additional elements http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 4 of 14 through its thickness Using Cubit s standard refinement operation the elements through the thickness would also be refined Improved preview for curve meshing The command panel for curve meshing Meshing gt Curve gt Mesh currently provides options for previewing the mesh prior to mesh generation This feature has been improved and made more consistent with this release of Cubit New Options in Curve Bias for Multiple Start Positions To mesh a set of curves with a bias often a start vertex Is required Previously the command syntax would only permit a single start vertex which would not allow specification of bias on multiple curves This enhancement changes the syntax for the curve bias command to accept multiple start vertices to allowing meshing of multiple curves simultaneously Geometry New Helix Curve and Volume Creation New commands to generate free curves and volumes defined as helix have been added This image on the left shows two helix curves generated with the c
20. ttp cubit sandia gov release_notes 13 1 html 2012 05 21 CO ie Rekat N Ot LEVEE Page 14 of 14 OF general technical quest BAS SH PWR Atal PHY Pea Feteksad VSR SFG US ioyed to the t bit helo sandia g ni n e n n ME eee 32 bit Version 13 1 with GUI The latest released version of CUBIT deployed to the LAN CUBIT Licensing and Passwords cubit nogul 64 bit Version 13 1 Command Line only with graphics window cubit Gieyieieezyraphics 64 bit Version 13 1 Command Line only without graphics window Cubit Licensing cubit 28dhe 505 284 6464 64 bit Version 13 0 with GUI cubits 2rBg pe sandla doy t Version 13 0 with GUI CubIFIsaia port Lead Version 13 1 beta The latest beta version still in development Bob Kerr i m ASabit SupberE cadeo m te na Phone 505 844 8606 Email rakerr sandia gov CUBIT Project Lead Byron Hanks sandia National Laboratories Computational Simulation Infrastructure org 1543 Phone 505 845 0500 Email bwhanks sandia gov Back to top of page Home Licensing Tutorials Documentation Support Downloads Links Sandia Corporation Site Contact Site Map Privacy and Security http cubit sandia gov release_notes 13 1 html 2012 05 21
21. ve available to perform the refinement To use this feature first create a course mesh for your model Then using the command below two files will be created that can be used in an external stk_adapt process Refine Parallel Fileroot lt root filename gt Overwrite No geom No execute Processors lt int gt Numsplit lt int gt Version lt Sierra version gt stk_adapt can also be run directly from Cubit if the executable is in the correct path When running stk_ adapt a series of mesh files one for each processor will be generated on disk that have been refined or subdivided based on the numsplit option The ability to refine to the precise smooth geometry definition is also available in this beta release http cubit sandia gov release_notes 13 1 html 2012 05 21 CUBIT 13 1 Release Notes Page 11 of 14 os g The left image shows an initial hex mesh generated in Cubit with 2365 hexes The right image displays a uniformly refined mesh using stk_adapt with 20 processors The result is about 1 35 million hexes where the colors represent the different processors used in the refinement Defeaturing Power Tool A new power tool has been introduced as a beta feature in Cubit 13 1 for defeaturing solid models where the defeaturing process is reduced to a single button click or command After using the set dev on command this tool is available from the tabs in the tree view window Selecting the analyze button will
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