Meshing Basics

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Meshing Basics

• Setting Meshing Schemes and Parameters

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Surface Map SubMap

• Structured meshes
• sides of swept volumes

Map
Submap
3
Pave
4
TriPrimitiveformerly triangle

• Quadrilateral elements
• 3-sided surfaces

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Circle

• Convex surfaces

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Hole

• Circle without center

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TriMesh TriDice

• Triangular elements, tri
• Trimesh TriAdvance, TriDice

TriAdvance
TriDice
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Exercise 5 Surface Meshing
Step 1 Import Acis file schemes.sat
Go to MeshingSurfaceMesh
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4
2
5
3
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Exercise 5 Surface Meshing
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Exercise 5 Surface Meshing
Step 2 Set the interval size for all the
surfaces to 1.0
Go to MeshingSurfaceMesh
Enter all to select all surfaces
1.0
Command line shortcut CUBITgt surf all size 1.0
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Exercise 5 Surface Meshing
Step 3 Mesh each front surface. Use scheme map,
submap, pave, circle, and hole. Try remeshing
each surface with a different scheme
Set mesh scheme here
Advanced scheme options
Set scheme only (do not mesh)
Mesh with current scheme
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Volume Map Submap

• Submap

• Map

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Sweep

• 2.5d - may twist turn
• sources targets unstructured
• sides structured

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Sweep, typical
inner to outer shell
rotate
translate
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Sweep

• Most volumes meshed with scheme sweep
• Rules to remember
• Linking surfaces must be meshed with scheme map
  or submap
• Multiple source surfaces allowable
• Sweep to single target surface
• Most geometry modifications done to make model
  sweepable

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Sweep Mesh Scheme Setup
Go to MeshingVolumeMesh
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1
Select Mesh Scheme Sweep
Select Source Surface
Comment Make sure mesh is deleted first
3
Select Target Surface
Comment Curve and vertex types set automatically
in 4.0 Use corner picking tab in 3.1
Apply scheme and mesh
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Sphere
cut-away view
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TetPrimitiveformerly Tetrahedron

• Hex elements
• Uses 1/4 cones, 4-sided volumes

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TetMesh

• Tetrahedral elements, tet

• Scheme thex for tet-gthex mesh

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Mesh Conversion Commands

• Mesh first, then convert w/ command
• Qtri, quad to tri
• also a scheme, specify base quad scheme
• Tquad, tri to quad
• Thex, tet to hex
• Htet, hex to tet

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Exercise 6 Volume Meshing

• Step 1 Import Acis file schemes.sat or reset the
  volumes
• Command line CUBITgt reset vol all
• Step 2 Set the interval size for all the volumes
  to 1.0
• Command line shortcut CUBITgt vol all size 1.0
• Step 3 Mesh each volume with scheme map, submap,
  or sweep
• Refer to Sweep Mesh Scheme Setup slide for
  help with sweep scheme
• Reminder Sweeping Rules
• Linking surfaces must be meshed with scheme map
  or submap
• Multiple source surfaces allowable
• Sweep to single target surface

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Scheme Auto Selection

• Definition
• Not a scheme, but automatically sets a scheme
  (usually).
• Scheme Auto selects
• Surface pave, map, submap, triangle
• Volume sweep, map, submap
• depends on surface schemes

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CUBIT Meshing Process Review

• CUBIT meshing steps

• Set Size Properties
• Mesh Size
• Auto Size
• Set Schemes
• Auto scheme
• Manual
• Match Intervals (usually automatic)
• Generate Mesh

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Exercise 7 Auto Scheme

• For each surface in schemes.sat set the scheme to
  auto calculate. What scheme did CUBIT choose?
  Were scheme circle or hole ever chosen?
• Do the same for the volumes. What schemes are
  selected? What source and target surfaces were
  selected for sweep volumes?

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MeshingVia Command Line

• Set size - must be unmeshed
• Curve 10 interval 3
• Volume all size .5
• Volume all size factor 2
• Volume all size autofactor ltfloatgt
• Volume 1 size smallest curvefactor ltfloatgt

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MeshingVia Command Line

• Set scheme - must be unmeshed
• Volume all scheme auto
• Volume 1 scheme auto
• Volume 1 scheme sweep
• Volume 1 scheme sweep
• source surf 7 target surf 4
• Mesh
• Mesh volume all