Q: Where can I download the latest version?
A: From LSTC's FTP Site.
Q: How can I scale an entire model or a portion of a model?
1. With a keyword file loaded, go to the FEM¡ú Element Tools ¡úTransform ¡ú Scale Interface .
2. Choose the appropriate local or global Scale Direction (ex: Global XYZ)
3. Enter the desired Scale Factor (ex: 25.4)
4. Choose scaling origin by Pick node or NodeID or XYZ coordinate (ex: 0,0,0)
5. Use the Gen Select Interface to select the portion of the model to scale
6. Click Scale Up or Scale Down
7. Click Apply or Done to commit the operation
Q: How can I save display settings for a model so that they can be easily reapplied later?
1. With a keyword file or d3plots loaded, choose Misc. ¡ú Start Recording Commands from the top menu bar
2. Enter a Macro Name and click Ok
3. Do blanking, turn parts on/off, change colors, change transparency, etc...
4. Choose Misc. ¡ú Stop Recording Commands
5. Use Misc. ¡ú Launch Macro Interface to load or execute a saved macro
Note: This approach can be useful for quickly reapplying settings after doing a File ¡ú Update.
Q: How can I play an animation and display a corresponding results curve simultaneously?
1. Load your d3plot files
2. Generate the desired curve using the XY Plotting Interface
3. Click Oper
4. Activate the "Timeline" checkbox in the lower right portion of the XY Plot window
5. Click Play in the Animation Controls Interface
Q: How do I get a force-deflection curve?
A: When you process ASCII files or time history data, individual or selected curves can be saved using the Save option in the XY Plotting window. If you have force-time and displacement-time curves, you can use the Cross option on the FEM ¡ú Post ¡ú Xyplot Interface.
Q: How can I generate movies (AVI)?
1. Use File menu to load d3plots (File ¡ú Open ¡ú Binary Plot)
2. Select File ¡ú Movie...
3. Click Start
Q: How can I save images (PNG, GIF, TIFF)?
1. Select File ¡ú Print... from File menu
2. Select image format (PNG, GIF, TIFF, etc...)
3. Click Print
Q: How can I process ASCII time history files?
1. Go to the FEM¡úPost ¡ú ASCII Interface
2. Select file type from the list (glstat, matsum, etc...)
3. Click Load or File (former loads file if in current directory, latter opens file selection dialog)
4. Select desired entity from first list (example: node ID)
5. Select desired component from second list (example: x-displacement)
6. Click Plot (XY Plotting window pops up with time history curve)
Q: How can I filter time history data?
1. In XY Plotting window, click Filter
2. Select filter type (SAE, BW, FIR100, COS)
3. Select appropriate time units (SEC, MILLISECOND, MICROSECOND)
4. Select desired frequency (20, 50, 60, 180, 300, 600, 1000) or enter the desired cutoff frequency in the text field
5. Click Apply
Q: How can I check for and fix initial penetrations?
A: Please refer to the Application¡úModel Checking ¡ú Contact Check Interface page
Q: Can LS-PrePost do surface meshing?
A: The FEM ¡ú Element and Mesh ¡ú Auto Mesher Interface provides 2 types of mesh mode: Size and Deviation
Q: How can I renumber model entities (nodes, elements, parts, etc...)?
A: Use the FEM¡úModel and Part¡ú Renum Interface. The entire model can be renumbered, or individual keyword types can be renumbered or offset. All associated data will be adjusted automatically. Renumbering and/or offsetting can also be perfomed while using the Save Keyword Dialog.
Q: Can I run LS-PrePost in batch mode?
A: Most operations can be performed in batch mode. Typically LS-PrePost is used in batch mode for extracting data from ASCII files. To run LS-PrePost in batch mode, use LS-PrePost c=commandfile -nographics, where "commandfile" is the file containing LS-PrePost commands.
Q: How can I write input file in a deformed configuration?
1. Using the animation controls, display the state to output
2. Go to the FEM¡úPost ¡ú Output Interface
3. Select a format (Keyword, Movie BYU, Nastran, Dynain, InitDisp, STL)
4. Select Active Parts Only or Entire Model
5. Select desired data (Element, Nodal Coordinates, etc...)
6. Click Current to select the state
7. Click Write (pops up file selection dialog)
8. Enter output file name and click OK
Q: Can LS-PrePost read Nastran bulk data file?
A: Most Nastran bulk data is converted to LS-DYNA keyword data with a few exceptions. The remaining data can typically be created in LS-PrePost. Alternately, LS-DYNA has facilities to read Nastran files using *INCLUDE_NASTRAN. This allows users to run NASTRAN input files directly in LS-DYNA, and all data conversion is handled by LS-DYNA.
Q: Can LS-PrePost animate multiple models simultaneously?
A: By using File ¡ú Open ¡ú Binary Plot, any number of models can be loaded into LS-PrePost. All loaded models are listed in the FEM¡úModel and Part¡ú Model Selection Interface. All models or any combination of selected models can be viewed together, and each model can be individually translated for making side by side comparisons (models can of course be directly overlaid as well). Using the FEM¡úModel and Part¡ú Part Color Interface, each model can be assigned a unique color to help identify differences.
Q: Can LS-PrePost do hex meshing from CAD surface data?
A: HEX meshing capabilities are currently under development, but if the surfaces is closed and mappable or mappable after decomposition, the FEM ¡ú Element and Mesh ¡ú Solid Mesher Interface can work well.
Q: Can LS-PrePost do tet-meshing?
A: Tet-Meshing can be performed using the FEM ¡ú Element and Mesh ¡ú Tetrahedron Mesher Interface. The input mesh can be either a solid or shell part. If the input is shells, then they must form a closed volume.
Q: How can I overlay curves (ex: analysis over test)?
A: External XY data can be imported into LS-PrePost using the FEM¡úPost ¡ú Xyplot Interface.
Q: Can I graphically display contact definitions?
A: There are two methods:
1. Use the FEM¡úModel and Part¡ú Keyword Manager Interface, double click *Contact_keyword. Then, on the keyword form, click Draw.
2. Use FEM¡úModel and Part¡ú Display Entity Interface
Q: How can I merge separate keyword files into one model?
1. File ¡ú Open ¡ú Keyword
2. File ¡ú Import ¡ú Keyword
3. File ¡ú Import ¡ú Keyword
4. etc...
Q: How can I animate a section cut?
1. Use the FEM¡úModel and Part¡ú Section Plane Interface
2. Define a plane and click Cut
3. Use the animation controls in the bottom toolbar to animate
Q: What is the difference between Group and View?
A: Group refers to a colletion of full parts. View can contain full and partial parts.
Q: How can I overlay a deformed shape on an un-deformed shape?
A: Use the FEM¡úPost¡ú State Interface
Q: How can I find free edges and merge duplicate nodes?
A: Click Show Free Edges on the FEM¡úElement Tools¡ú Duplicate Nodes Interface
Q: What does the History interface do? Why would I want to use it?
A: The FEM¡úPost¡ú History Interface is for plotting time histories of nodes, elements, materials (parts), and global data. This data can be from d3plot, d3thdt, or d3iff files which are binary files output by LS-DYNA.
Q: Can I calculate any injury criterion in LS-PrePost?
A: HIC (Head Injury Criterion) and CSI (Chest Injury index) can be calculated in 4 different ways:
1. From the d3thdt file using the FEM¡úPost¡ú History Interface
2. From ASCII files using nodout file
3. From ASCII files using rbdout file
4. From XY Plotting window by clicking Oper and using Hic36
The gravitational constant and time units need to be selected to match the unit system you are using. This can be done by adjusting the Hic/Csi const. on the FEM¡úPost¡ú Setting Interface.
Q: Can I use my own forming limit curve?
A: FLD files can be imported through the FEM¡úPost¡ú FLD Interface by clicking Browse
Q: Can I display nodal time histories with respect to a rotating coordinate frame?
A: No. Time histories with respect to rotating coordinate frames have to be requested as LS-DYNA output using *DATABASE_HISTORY_LOCAL or *ELEMENT_SEATBELT_ACCELEROMETER and *DATABASE_NODOUT in LS-DYNA input files. The ASCII nodout file can then be processed using the FEM¡úPost¡ú ASCII Interface.
The distance between 2 nodes can be measured and time histories of displacements in global and local coordinate system can be plotted using the FEM¡úElement Tools¡ú Measure Interface. This can be done while d3plot files are loaded for post-processing.
Q: What is *PARAM?
A: *PARAM is an LS-DYNA keyword. It allows users to define variables that can be assigned other keywords. Each keyword form has facilities to assign parameters. This capability can be used for optimization studies.
Q: Can LS-PrePost handle master weld files?
A: LS-PrePost supports a number of masterweld file formats. Please refer to the FEM¡úElement and Mesh¡ú Spot Welding Interface.
Q: How can I output displayed parts only as a keyword file?
A: Once you have loaded a keyword file into LS-PrePost and displayed some parts, you can output a keyword file of only the active (displayed) parts using File ¡ú Save Active Keyword As .
Q: Can I rearrange the right toolbar?
A: All icons on the right toolbar can be re-configured, and this is done using Settings ¡ú Toolbar Manager. This preference can be saved in the Configure_Toolbar.cfg file of the %appdata%/LSTC/LS-PrePost/ directory for windows and the $HOME/.lspp/ directory for linux.
Q: How can I share a partial set of results or partial animation if my full set of d3plots is too large?
A: Use File ¡ú Save post.db. This interface allows saving lspost database files for selected elements or parts.
Q: How can I just save displacements?
A: The lspost database is designed to meet these needs. An lspost.db file can be created by extracting specific data from d3plot files or interactively in LS-PrePost. Only active as well as entire model can be saved as an lspost.db file. Please refer to commandfile documentation for more information.
Q: Can LS-PrePost project nodes to a mesh or a curve?
A: Use To Curve and To Mesh on the the FEM¡úElement Tools¡ú Transform¡úProject Interface
Q: If I rotate a part that has stresses from a previous run, does LS-PrePost rotate the stresses?
A: Typically in metalforming applications, a dynain file containing thickness, stresses, and strains is output at the end of a stamping simulation. The stresses and strains are output in the keyword card definitions like *INITIAL_STRESS_SHELL etc... If such data is present in the model, and these parts get rotated, LS-PrePost rotates the stress and strain data accordingly.
Q: How can I post-process ALE results in LS-PrePost?
1. Click the Isos Bottom Toolbar
2. Choose Fluid type on the FEM¡úModel and Part ¡ú Assembly and Select Part Interface
3. Click Misc for fluid components on the FEM¡ú Post ¡ú Fringe Component Interface
4. Choose Fluid Surfaces on the FEM¡ú Post ¡ú Output Interface
Q: Can I animate mode shapes from eigenvalue analyses?
A: d3eigv files from LS-DYNA eigenvalue analyses can be loaded as binary plot files. Upon loading d3eigv files, the LS-PrePost Animation Control Interface will change automatically to allow animation of mode shapes.
Q: How can I plot time histories of all integration points through the shell thickness?
1. Choose Int.pt on the FEM¡ú Post ¡ú History Interface
2. Select shell elements from the display by left mouse clicking
3. Click Plot
Q: What is the difference between File ¡ú Open and File ¡ú Import?
A: Open reads the model in as a new model. Import appends the data to an existing model.
Q: What type of CAD data can LS-PrePost import and export?
A: IGES and STEP
Q: How can I fit belts to a dummy model?
A: Use the Application¡ú Seatbelt Fitting Interface
Q: Is there a way to find and delete unreferenced data in my model?
A: Use the Application¡ú Model Checking interface, click Model Clean ¡ú Setting to find unreferenced data and to delete data by clicking AutoFix in Model Clean interface.
Q: What airbag folding methods are available in LS-PrePost?
A: thin, thick, tuck, spiral, and scrunch (see theApplication¡ú Airbag Folding Interface)
Q: Can I create initial velocities in a local coordinate system?
A: Initial velocities can be assigned to nodes using the FEM¡ú Model and Part ¡ú IniVel Interface. Use Create Type=Local, and select a local CS from the list (the coordinate system must be pre-defined).
Q: Can I convert model units in LS-PrePost?
A: Direct unit conversion is not currently available in LS-PrePost, but LS-DYNA provides a method for converting model units using *INCLUDE_TRANSFORM, and this keyword can be setup in LS-PrePost.
Q: What are some other good sources of LS-DYNA related information?
A: Links to LS-DYNA information on the web:
LS-DYNA Examples (dynaexamples.com)
LS-DYNA Papers (dynalook.com)
LS-DYNA Support (dynasupport.com)