LSTC_PhilipHo_Symposium07

2003 Livermore Software Technology Corporatio

LS-PREPOST

Capabilities ofCapabilities of LSLS--PREPOST2.1 PREPOST2.1

1818thth Annual HP Symposium:Annual HP Symposium:Technology Trends in Computational Technology Trends in Computational

EngineeringEngineering

Plymouth, MichiganPlymouth, Michigan

Philip HoPhilip Ho AprilApril 3rd, 20073rd, 2007


LS-PREPOST

OverviewOverview

LSLS--PREPOST is a combined prePREPOST is a combined pre--processor processor and postand post--processor for LSprocessor for LS--DYNADYNAProvides baseline pre- and post-processing

support for LS-DYNA usersFull support of LS-DYNA keywordsFull post-processing capabilities for LS-DYNACoupling of LS-DYNA input data with output

results


LS-PREPOST

OverviewOverview

Geometry data and meshing Mesh editing and checking Model creation and editing LS-DYNA keyword editing Applications Dummy positioning Seatbelt fitting Airbag folding Metal forming


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OverviewOverview Applications SPH particles generation 201 head impact position IIHS intrusion measurement

Post-processing Time sequence animation Fringe, contour, and iso-surface plots Time history plotting Cross sectioning Multiple models results on same screen


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Other Imported file formatOther Imported file format

Other input files that can be importedOther input files that can be importedNastran bulk data (commonly used data)I-Deas universal file (elements and nodes)Ascii or Binary formatted STL filesIges and VDA geometry data


LS-PREPOST

Geometry and MeshingGeometry and Meshing

Curves/Lines interfaceSurface interface2D-MeshingSimple Geometry MeshingTetrahedron mesher and surface re-meshN-line meshingSurface meshing3D Block meshing


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Geometry Geometry Curves/LinesCurves/LinesPage 2 or Page 7 Curves To show/create/modify

curves/linesCurves can be created by inputing the xyz

coordinate of a point.Or from picking positions on the existing meshOr from picking an edge of an elementOr imported from an Iges file, Vda, or piecewise

data points formatArcs or circle can easily be createdThe total length of a curve can be computed Curves can be exported in Iges/Vda/xyz format


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Geometry Geometry Curves/LinesCurves/Lines

Curve Creation by picking edge with propagation


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Geometry Geometry Curves/LinesCurves/Lines

Curve Modification operationBreak CurveJoin CurveRename CurveDelete PointsInsert PointsTranslate CurveRotate CurveSmooth CurveRe-space Curve


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Geometry Geometry Surface InterfaceSurface Interface

Page 7 Surface To show/create/modify/delete and export surfacesSurfaces can be imported via Iges or Vda filesSurfaces can be created by 2/3/4line that form the

boundary


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Geometry Geometry Surface InterfaceSurface Interface

Page 7 Surface Creation/DeletionSurfaces can be created by lines that define the

skin of the surfaceSurfaces can be deleted from the geometrySurfaces data can be exported in Iges/Vda format


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Meshing Meshing 2D Mesher with sketch board2D Mesher with sketch board

2Dmesh 2Dmesh is the magic mesher from Mazeis the magic mesher from Maze2d sketch board to create points, lines, arcs and

curvesUse curves to form outline of mesh Define mesh density on the outlines of the

geometry


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Meshing Meshing Simple GeometrySimple Geometry

To generate simple shape geometriesBox (Cube) define min and max pointsFlat Shell define 4 pointsCylinder define radius, and vector along the cylinderSolid or Shell can be capped or hollow

Sphere define radius, and density which is the no. of elements in a 90 degree segmentSolid or Shell


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Simple Geometry MeshingSimple Geometry Meshing


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Tetrahedron Mesher and Surface RemeshTetrahedron Mesher and Surface Remesh

A solid tetrahedron mesh is produced from a good enclosed surface mesh.Distorted, or rather irregular surface meshes will

not produce a good tet mesh. The surface must be cleaned up by merging small triangles, and remeshing.A solid part can be skinned and used as an enclosed

surface.Skin only form a connected solid. Later skin an

unconnected solid by selecting the outer surface


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Skin a Solid HemisphereSkin a Solid Hemisphere


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TetMesh InterfaceTetMesh Interface


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Tetmeshed and showing inside meshTetmeshed and showing inside mesh


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Meshing Meshing -- NLMeshNLMesh

Page 7 Page 7 -- nLMesh nLMesh 2 Line shell Create shell mesh between 2 curves 3 Line shell Create shell mesh bounded by 3 curves 4 Line shell Create shell mesh bounded by 4 curvesLine Sweep - Create a mesh by sweeping one line along

another lineMeshing density can be selected fromNo. of elements on lineElement sizePoint of line


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Meshing Meshing -- NLMeshNLMesh


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Meshing Meshing -- nLMesh Line SweepnLMesh Line Sweep


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Sweep 2D CrossSweep 2D Cross--section into Solid section into Solid

Page 2 Page 2 ElGenElGen-->Solid>Solid-->Solidby Shell >Solidby Shell SweepSweepSelect cross-section shell elementsSelect curvesAssign number of elements along the

curvesTurn on Keep AngleTurn on Keep Cross-section


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Sweep 2D CrossSweep 2D Cross--section into Solid section into Solid


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Surface Meshing Surface Meshing TMesh and AMeshTMesh and AMesh

Automatic surface meshersAutomatic surface meshersTmesh tool meshing for metal stampingAmesh topology meshing for regular

modelRead Iges or Vda geometry fileSelect surfaces to be meshedEnter meshing parametersMesh it, accept or reject mesh


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3D Block Solid and Shell Meshing3D Block Solid and Shell Meshing

3D block mesher uses LS-Ingrid index space mapping methodBoth Shell and Solid can be createdSingle block, Multiple blocks and

Butterfly block are the block typesI,J,K index lists define spacing for

the blocksX,Y,Z position lists define the

actual postion of the blocks


LS-PREPOST

3D Block Meshing3D Block Meshing

Computation window provides the block topology in graphical formComputation window also provide manipulation on

the mapping projectionWhen physical model rotated graphically, the

computation blocks also rotated accordingly. The viewing of the physical model and the computation blocks are in sync.


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Using negative numbers in the index list to indicate it is shell mesh instead of solid meshWhen there is negative number

in the index list, it represents shell model, positive numbers just give space index, will not generate shellSolid mesh and shell mesh do not

mixed


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Parameters and expression can be usedEquations also can be usedParameters and expressions

are case sensitiveCoordinates can be

evaluated by equations


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Mesh Clean UpMesh Clean Up

Mesh clean up can be done by Mesh clean up can be done by EleditEledit, , DupgridDupgrid, , NormalsNormals, and other interfaces, and other interfacesDupgrid Merge duplicated nodes and delete collapsed

elementsNode replace merge nodes by picking 2 nodesElement deletion and creationAlign nodes Split elementsReverse shell normal


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Mesh Data ManipulationMesh Data Manipulation

Mesh data can be manipulated or copied by Mesh data can be manipulated or copied by TranslateOffsetScaleRotateProjectReflectTransformDetach


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Input keywordInput keyword

Import multiple keyword Import multiple keyword files, each file is defined files, each file is defined as a subsystem.as a subsystem.

ID Offset can be set to ID Offset can be set to the largest values or user the largest values or user input valuesinput values

All Keyword cards can All Keyword cards can be viewed in a tree formbe viewed in a tree form


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LSDYNA Keyword dataLSDYNA Keyword data

Each keyword has its own form Each keyword has its own form for input and editingfor input and editing

Keyword data that is present in the Keyword data that is present in the model will be highlighted with model will be highlighted with blue colorblue color

There are over 900 keyword There are over 900 keyword entitiesentities

Comment cards, title cards are Comment cards, title cards are available for each keyword inputavailable for each keyword input

Parameters and Expression are Parameters and Expression are supported

Pag3 and page4 for all keywords

Edit keyword by list

Keyword edit operation buttons

supported


LS-PREPOST

Keyword Edit Keyword Edit -- FeatureFeature

Keyword Selection Menu CONTROL Extra Keyword

Options Ref By Interface and save ref

to buffer Link Keyword Dialog Pick interface Entity Draw Option Input data by table Transfer Material data from

Material Database Plot curve and sort section data

Read data Link Dialog


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Keyword Edit Keyword Edit -- FormForm

Keyword input forms Keyword input forms match LSmatch LS--DYNA manualDYNA manual

Each data field is Each data field is identified by its nameidentified by its name

The description of the The description of the field is shown with a field is shown with a simple click in the field or simple click in the field or the field namethe field name

Simple selection button is used for the data field with preSimple selection button is used for the data field with pre--defined valuesdefined valuesA popup table can be used as an aid to transfer data to the seleA popup table can be used as an aid to transfer data to the selected fieldcted fieldLink data can be viewed with a click on the nameLink data can be viewed with a click on the name


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Save Keyword FileSave Keyword File

Save keyword data into fileSave keyword data into file Save in LS960, LS970, and LS971

format Advanced options

Output keyword data in users own sequence

Output keyword data selectively Output keyword data with title Output parameter names instead of

actual data Output field names Output comments

Renumber data IDs Offset data IDs Output subsystems in different files


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Application Application Dummy PositioningDummy Positioning

Occupant PositioningOccupant Positioning Occupant positioning provides an interface to

manipulate the occupant which can be integrated into another simulation.

Users can rotate, translate or reflect the dummy along and about specified directions.

Each connected limb of the occupant can be moved about its joint defined in the corresponding tree file.

All constrains and physical properties will also be transformed along with the geometry data.

Multiple occupant control and importing are also supported.


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Application Application -- Airbag FoldingAirbag Folding

To create fold definition and fold an airbagTo create fold definition and fold an airbag Fold types

Thin, Thick, Tuck, Spiral Fold line does not have to be on element edges Not limit to XY plane Step by step folding Save and load fold definitions Fold definition can be modified Animate fold process to give better visual effect


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Application Application Seatbelt FittingSeatbelt Fitting

To create and fit a seatbelt across occupantTo create and fit a seatbelt across occupant By defining Set_Segments and a few control

points on the segments Create simple belt (*Element_seatbelt) Create mixed belt (*Element_seatbelt and Shell

elements) User defined element size, and belt width Allow stretching to give best fit


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SPH GenerationSPH Generation

Sphgen To create SPH particles with different fill level

Create SPH by the following methodsBox define min/max pointsSphere define position and radiusCylinder define position, radius and length

along with the direction of the cylinderFromHex Hex parts, use existing nodesPartlist Enclosure by shell parts

Pitch distance between particles Density is used to compute particle mass Fill level can be less than 100% Give direction of gravitational force


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Created By Partlist Only Shell parts can be used Can use multiple parts Shell parts should form an water tight enclosed

volume Normals of shell should be consistent and

pointing outward, this limitation will be eliminated soon

Shell thickness will be taken into account for particles close to the boundary


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Metal Forming InterfaceMetal Forming Interface

Combine many functionalities Combine many functionalities into one single interface for into one single interface for stamping applicationstamping application

Allow users to define components Allow users to define components such as Die, Punch, Binder, such as Die, Punch, Binder, Blank, Blank, DrawbeadDrawbead, etc., etc.

Allow users to define different Allow users to define different stages of the stamping processstages of the stamping process


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201 Head Impact Positioning201 Head Impact Positioning

Read in head and locate Read in head and locate positionposition

Multiple heads can be Multiple heads can be positioned in the same modelpositioned in the same model

Head can be tilted vertically or Head can be tilted vertically or rotated horizontally rotated horizontally interactivelyinteractively

Configuration file can be setup Configuration file can be setup to have head model loaded to have head model loaded automaticallyautomatically

Multiple LSMultiple LS--DYNA keyword DYNA keyword files will output for each head files will output for each head positionspositions


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IIHSIIHS

nodout

123 345 567

34546

65465

343425

4546575655

56788

45466

5656 6546

57643456

656754


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PostPost--ProcessingProcessing

LSLS--PrepostPrepost provides full postprovides full post--processing processing capabilities for LScapabilities for LS--DYNA result filesDYNA result files D3plot files D3thdt files Interface force file All Ascii files Binout file


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PostPost--ProcessingProcessing

Post-processing functionalities include Animation Components fringe/contour plot Stress/Stain vectors plot Cross section plot Time history data plot Time history cross plot Fluid part iso-surface plot Volume fraction history plot for ALE fluid


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Vector MenuVector Menu

Nodal Surface Shear

Principal Strain

Velocity


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Time History InterfaceTime History Interface

History History to plot time history datato plot time history data Element dataElement stresses and strainsPick elements to plot dataValue set to element value or min/max value for the

partE-Type choose element type to plot historyE-Axes global or localSurface choose shell element through the thickness

locations Scalar plot scalar value that is being fringed (choose

component in Fcomp interface) Int.pt Select element integration points


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XYPlot XYPlot show and cross plottingshow and cross plotting

Import xy plot data as: list of points, keep file, and curve file

All xy data saved in the xy plot windows is automatically add to the file list.

Files can be added by the File menu or Add button. Remove button deletes file from list.

All plot windows open are also listed under the Window toggle button.

So any point data can be shown and added to a current plot.

When data from one plot is required to be related to another plot, so called cross plotted can be used


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XY plot XY plot cross plotcross plot

Two files are added to file list

Select 2nd file, and each curve in file is then listed

Select curve into X-axis location

Do the same for 1st file into Y-axis location

Press plot button Stress versus Strain plot


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AnnotationsAnnotations


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XYPlot WindowXYPlot Window


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XYPLOT WindowXYPLOT Window


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Formatted OutputFormatted Output

Purpose: To output postPurpose: To output post--processing data into processing data into various formatted filevarious formatted file Option for whole model or active parts only Output in user Ids or internal Ids Output model itself or with nodal/elemental

results State no selection Format selection:KeywordNastranDynainSTL ascii or binary


LS-PREPOST

LSLS--Prepost_VRPrepost_VR

LSLS--Prepost_VRPrepost_VR: A special version of : A special version of lsprepostlsprepost to run to run on large screen multion large screen multi--wall systemwall system It is built on VR Juggler (http://www.vrjuggler.org), an open source

framework for building virtual reality applicationsWand-based interaction LS-Prepost_VR supports interfaction via

a 6-dof wand. The wand controls the model manipulation (rotate, translate, scale), animation and selection, also an interactive clipping plane to explore the dataset

LS-Prepost_VR is free just like LS-Prepost, but requires installation Fee. (cost is systems dependent, contact LSTC for the cost)


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LS-PrePost-VRRender Nodes

LS-PrePost-Remote(client) LS-PrePost-VR

(server)

Wireless Access Point

10/100 Network Switch


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Head Avatar Clip Mode Indicator

Virtual Wand Pointer


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Current Status of LSCurrent Status of LS--PrepostPrepost

LS-Prepost is bundled with LS-DYNA on all hardware/software platforms including PC/Windows without additional cost

LS-Prepost 2.1 has been released LS-Prepost 2.1 can be freely downloaded from

ftp://ftp.lstc.com/outgoing2/lsprepost2_1 64bit version is available for both Unix,

Linux, and Win64


LS-PREPOST

Current Status of LSCurrent Status of LS--PrepostPrepost Online documentation is available at

http://www.lstc.com/lspp There are more than 16 extended tutorials and

many mini-tutorials online that give step-by-step instructions on how to create and generate model data. More tutorials will be added over time

FAQ (Frequently Asked Questions) is also available online to help users

Linkage to other LS-DYNA support sites


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ConclusionsConclusions

Making LS-Prepost more stable and more robust is always our number one prioritySupport LS-DYNAs pre- and post-processing

needs is our major goals and objectivesFulfill users demands whenever it is possibleWilling to listen to users suggestions and

adapting new ideas

Capabilities of LS-PREPOST2.1 18th Annual HP Symposium:Technology Trends in Computational EngineeringPlymouth, MichiOverviewOverviewOverviewOther Imported file formatGeometry and MeshingGeometry Curves/LinesGeometry Curves/LinesGeometry Curves/LinesGeometry Surface InterfaceGeometry Surface InterfaceMeshing 2D Mesher with sketch boardMeshing Simple GeometrySimple Geometry MeshingSimple Geometry MeshingTetrahedron Mesher and Surface RemeshSkin a Solid HemisphereTetMesh InterfaceTetmeshed and showing inside meshMeshing - NLMeshMeshing - NLMeshMeshing - nLMesh Line SweepSweep 2D Cross-section into SolidSweep 2D Cross-section into SolidSurface Meshing TMesh and AMesh3D Block Solid and Shell Meshing3D Block Meshing3D Block Meshing3D Block Meshing3D Block Meshing3D Block Meshing3D Block Meshing3D Block MeshingMesh Clean UpMesh Data ManipulationInput keywordLSDYNA Keyword dataKeyword Edit - FeatureKeyword Edit - FormSave Keyword FileApplication Dummy PositioningApplication - Airbag FoldingApplication Seatbelt FittingSPH GenerationSPH GenerationSPH GenerationMetal Forming Interface201 Head Impact PositioningIIHSPost-ProcessingPost-ProcessingVector MenuTime History InterfaceXYPlot show and cross plottingXY plot cross plotAnnotationsXYPlot WindowXYPLOT WindowFormatted OutputLS-Prepost_VRLS-Prepost_VRLS-Prepost_VRCurrent Status of LS-PrepostCurrent Status of LS-PrepostConclusions

LSTC_PhilipHo_Symposium07

Documents

vda geometry data

lsdyna input data

iges file

processor processor

file formatother input

dyna keywordsfull

processing support

importednastran bulk