The Meshing Toolbox · 2017-11-15 · –Mesh geometry and interactively refine meshes. –Locate mesh for editing. –Allows viewing of mesh quality. •Help for the Meshing Toolbox

5/22/2012

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IN THIS WEBINAR:

• Manipulate and Idealize Geometry

• Interactively Create and Manipulate

Mesh

• Check and Edit Mesh Quality

The Meshing Toolbox10 Tools to Quickly Create and Refine

Accurate Finite Element Models

Russ Hilley

Senior Aerospace Stress Engineer

Structural Design and Analysis

[email protected]

PRESENTED BY:

mailto:[email protected]

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Page 2STRUCTURES.AERO

Structural Design and Analysis (Structures.Aero)

Structural Analysis

• Team of stress engineers that help our clients

design lightweight and load efficient structures.

• We service aerospace companies and other

industries that require high level analysis.

• Specialty in composites and lightweight

structures

• Tools used include hand analysis, HyperSizer,

Femap, NX Nastran, Fibersim, NX, Solid Edge,

Simcenter 3D, LS Dyna, and LMS.

Software Sales and Support

• Value added reseller providing software, training,

and support for products we use on a daily

basis.

• Support Femap, NX Nastran, Simcenter 3D,

Fibersim, Solid Edge, and HyperSizer.

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Meshing Toolbox Topics

• What is it?– The meshing toolbox is a collection of tools which eases the geometry preparation, meshing,

and mesh refinement tasks.

• What does it do?– Locates features and mesh which can be improved.

– Prepares geometry by suppressing/removing features or adding/editing features to aid meshing.

– Mesh geometry and interactively refine meshes.

– Locate mesh for editing.

– Allows viewing of mesh quality.

• Help for the Meshing Toolbox– Section 7.2.2 of the FEMAP Commands Reference covers all of the Meshing Toolbox

Commands.

– Commands.pdf is found in the following folder.• C:\Program Files\Siemens\FEMAPv1141\pdf

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Inside the Meshing Toolbox

1. Toolbox Visibility –

Turn on or off individual tools as needed

2. Toggle Entity Locator –

Entity Locator isn’t on by default

3. Toggle Surface mesh quality – Show quality

attributes of the mesh.

4. Remesh Control – Mesh can be recreated

automatically with each change or changes

can be tracked to be implemented later.

5. Select or Select Dialog – Selects the

appropriate entity based on the tool in use.

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Entity Locator

• Common uses of the Entity Locator:

– Locate bad geometry: Curves or Surfaces which may not produce good mesh

– Locate bad mesh: Based on common quality attributes or edge length

– View Free Edges in geometry and mesh

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Quality Display

• Shows a 2 level plot of the Jacobian by default.

• Used in conjunction with the Surface Mesh

Quality tool to view other quality attributes as

well.

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Remesh Options

• Disable Remesh: Automatic remeshing does not occur as changes are being made.

The geometry will need to be manually remeshed when the remesh option is set to

Disable Remesh.

• Auto Remesh: Remeshes the geometry as changes are made

• Track Remesh Changes: The toolbox tracks changes made to the mesh or geometry

and allows all changes to be implemented at once.

• Remesh Entities: Remeshes the geometry and implements any tracked changes.

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Select

• Select: Allows entities to be selected one at a time or by using the Shift / Ctrl-

LMB and the Ctrl-Shift-LMB modifiers for a box, circle, or polygon pick.

– Entity type to be selected will change depending on the tool in use.

• Select Dialog: allows for the use of the FEMAP standard selection dialog box

along with the available methods and pick options for the entity type being

selected.

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Feature Suppression Tool

• As the name implies, the Feature Suppression

tool only suppresses the geometry and instructs

the mesher to ignore that feature.

• No permanent changes are made to the

underlying geometry.

• Features can be toggled easily from suppressed

to unsuppressed as individual features, all

features in a selected solid, or all features in the

current model.

• Suppressed features change colors to indicate

the feature is ignored by the mesher.

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Feature Removal

• The Feature Removal tool allows easy removal of features not needed for the

analysis.

– Loops – Circular holes or slots can be removed. A mesh point can be placed at the

center of round holes in the geometry.

– Curves

– Surfaces – Corner fillets, chamfers, holes

– Blends – Used to remove corner fillets, sheet metal bends in solids.

– Points – At unwanted breaks in curves

• Removal of Loops, Curves, Surfaces, and Blends can be limited by size so

that many features can be selected at once.

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Feature Removal

• Loops removed and mesh point left at the hole centers. Leaving a mesh point

forces the mesher to place a node at that location.

– Size was limited so that the rectangular opening was ignored in the loop selection.

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Feature Removal

• Surface Removal

– Selected using the dialog select and add connected fillets.

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Feature Removal

• Blends – Works well for parts with sheet metal bends

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Feature Editing

• The Feature Editing tool is commonly used to make basic changes to

geometry.

– Move / rotate surfaces

– Resize holes

– Edit or Offset surfaces

• Saves time for simple changes. Remeshing is done interactively as the

geometry is changed.

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Feature Editing – Resize Hole

• Resizing Holes

– Enter a new hole diameter and use the select or dialog select to select the edges of

the hole.

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Feature Editing

• Feature Edges – Translate Surfaces

– Used mostly with internal features such as holes or slots.

– Meshing is updated interactively.

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Feature Editing

• Also works to translate features which aren’t holes or slots on sheet bodies

created with the midsurface commands.

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Geometry Editing

• The Geometry Editing tool allows the user to divide surfaces efficiently to

create regions more suitable for mapped meshing.

• Meshed surfaces can also be edited. The mesh will be interactively updated

based on the Remesh control setting.

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Geometry Editing

• Pads and Washer regions allow for mapped meshing

regions around holes.

– Mapped meshing options are automatically set.

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Geometry Editing

• Washer and Pad combinations can also be created.

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Geometry Editing

• Point to Point, Point to Edge, and Edge to Edge options are used

to add curves to the surface which will aid in mapped meshes.

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Geometry Editing

• Extend allows the user to extend one surface.

– To intersect another surface or solid

– To a location or distance

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Geometry Editing

• Project / Move Point allows the editing of surface corner locations.

– Select the desired location and then the point.

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Meshing Toolbox – Geometry Editing

• Project Curve – Splits surfaces using a curve in much the same way the

Geometry – Curve From Surface commands.

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Combined / Composite Curves

• Forces the mesher to treat

a combined set of shorter

curves as if meshing a

single curve.

– Curves change color to show

a composite curve

– Creates a more uniform

mapped mesh.

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Combined / Boundary Surfaces

• The Combined / Boundary Surfaces tool works much the same as the

Composite Curves tool but combines 2 or more surfaces to create a

composite surface.

– The mesher is forced to mesh the composite surface.

– As with combined curves, surfaces change color to indicate a composite surface.

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Mesh Surface Tool

• The Mesh Surface tool contains all the functionality of the

Mesh – Geometry – Surface command.

– Attributes can be loaded from another surface

– Property Setting

– Sizing Options

– Element size and Shape

– Mapped or Free Mesh

– Advanced Options: Post mesh cleanup, smoothing…

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Mesh Surface Tool

• Property – Use Meshing Attributes

– Allows the use of predefined meshing attributes set either using the Mesh – Mesh Control

– Attributes on Surface command or the Midsurface – Assign Mesh Attributes command.

• Property – The property can be defined on the fly using the browse button or

select a predefined property card created using the Model – Property

command.

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Mesh Surface Tool

• Four Mesh Sizing options available.

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Mesh Surface Tool

• Mesh Sizing Options – Off

– Setting used to change Element Shape, Meshing Method or Advanced Options without

changing the element size on any surfaces.

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Mesh Surface Tool

• Mesh Sizing Options – Size All, Connect (Most common and default)

– Resizes all curves of the selected surface the new mesh size, then meshes/remeshes the

surfaces and updates the Mesh Size on all shared curves of connected surfaces. The

mesh will be connected through the transitions.

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Mesh Surface Tool

• Mesh Sizing Option – Size All, Disconnect

– Resizes the curves of the selected surface with the new mesh size and remeshes the

surface. No attempt is made to connect surfaces which share curves.

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Mesh Surface Tool

• Mesh Sizing Options – Size, Internal / Free Edges.

– Resizes the "internal curves” or “free edges” of the selected surfaces. All curves “shared”

by selected surfaces and non-selected surfaces will NOT be resized.

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Mesh Surface Tool

• Element Shape

– Linear 3 Node Triangles

– Parabolic 6 Node Triangles

– Linear 4 Node Quad

– Parabolic 8 Node Quad

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Mesh Surface Tool

• Free Mesh

– Max Quads – FEMAP will attempt to create an all quad free mesh minimizing the use

of triangle elements.

– Quad / Tri Layers – When set, this option will create the desired number of quad

element layers around internal boundaries such as holes or slots

– Min Elements Between Boundaries – The mesher will place the set number of

elements, up to 3 layers, between boundaries

– Show Free Edges – When enabled, this options highlights nodes on free edges.

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Mesh Surface Tool

• Mapped Mesh – Attempts to create a mapped quad mesh similar to using the

Mesh – Mesh Control – Approach on Surface command.

– Auto Approach – When enabled, FEMAP will determine the best approach for a given

selected surface. Disable this options to specify an approach using the same options

found in the Mesh Control – Approach on Surface command.

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Mesh Surface Tool

• Mapped Mesh

– Auto Mapped Approach enabled.

– Auto Mapped Approach disabled to manually select a desired approach.

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Mesh Sizing Tool

• The mesh sizing tool is used to set mesh size and node spacing on curves.

– Mesh interactively changes when mesh size is changed on curves if Auto Remesh is

enabled.

– Works best with plate meshes and tetrahedral meshes.

– Options are available for matching nodes or curves. This is similar to the Mesh – Mesh

Control – Custom size on curve command.

– Spacing options are available to bias the mesh toward the ends or middle of curves.

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Mesh Sizing Tool

• Size Curves

– Increase and Decrease will change the number of nodes on a curve by a set number of

elements or by a factor.

– Set to a desired number of elements on curves.

– Sizing changes can be propagated by mapped approaches.

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Mesh Sizing Tool

• Match Curves or Nodes

– Allows for the selection of one or more curves or nodes which will be matched on the

selected curve.

• Select the curve or nodes to match

• Select the curve to have the matching mesh

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Mesh Sizing Tool

• Spacing Options – Similar to the node spacing options in the Mesh – Mesh

Control – Size on Curve command.

– The spacing options are used to bias the mesh to one end, middle, or a selected bias

location of the selected curves.

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Mesh Locate

• The Mesh Locate tool allows moving one or more nodes dynamically without

changing the number of elements.

– Move nodes to represent a connection location

– Move nodes to improve mesh quality. The mesh locate tool can be used in conjunction

with the Surface Mesh Quality tool.

– Mesh to edit can be selected based on geometry or as a standalone mesh.

– If the Constrain to Curve/Surf is enabled, nodes will remain attached to the geometry

and cannot be dragged out of plane or off the edge of the surface. This is option is on

by default and is preferred.

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Mesh Locate

• Mesh Quality shown with original node locations and then moved to improve

quality.

– The changes can be saved or discarded in the Mesh Locate tool.

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Surface Mesh Quality

• The Surface Mesh Quality tool allows you to view mesh quality as a contour /

criteria plot.

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• Quality Source – Femap or Nastran

– The checks available in the pull down for each are the same checks and

default values used in the Tools – Check – Element Quality command.

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• The default is to show a contour / criteria of the Jacobian with a max value of

0.6.

– The value can be changed if needed.

– The contour / criteria can show 2 or 4 levels.

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• For any quality attribute chosen, the Surface Mesh Quality tool will show the

minimum and maximum values.

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For questions on the material covered

today, please contact Russ Hilley.

For questions about pricing, or to see a

demo, please contact Marty Sivic.

Questions?

Marty SivicDirector of Sales

[email protected]

724-382-5290

Russ HilleySenior Aerospace Stress Engineer

[email protected]

703-657-0919



Documents

The Meshing Toolbox · 2017-11-15 · –Mesh geometry and interactively refine meshes. –Locate mesh for editing. –Allows viewing of mesh quality. •Help for the Meshing Toolbox