Simcenter Testing Solutions Simcenter Testlab Neo: Geometry Creation

Direct YouTube link: https://youtu.be/K4G_NCzdo1A


Want to use Simcenter Testlab Neo (formerly LMS Test.Lab) to create Geometry before an Operational Data Animation (or Operational Deflection Shape) or Modal Analysis study?



This article describes using the Geometry Creation Add-in in Simcenter Testlab Neo to create a geometry from scratch, create standard shapes like a rectangle, prism, circle and cylinder quickly, select nodes from an existing CAD (*.stl or *.stlb) or CAE (Nastran, Ansys, Abaqus or Simcenter 3D) file and either manually create wires or use Autowire to connect the nodes. Simcenter Testlab 2021.2 was the first release of Neo Geometry Creation and it was expanded in 2206. Revision 2206 will be shown here.

Here is how to do it:
1. Where to find Geometry creation?
2. Using the Geometry Edit Task and Home Ribbon to Create Simple Geometries
3. Using the Geometry Edit Task and Add Ribbon to Add Simple Geometry Shapes and Autowire your nodes
4. Using the Geometry Import Task to Import Geometries, Automatically Reduce them and Autowire.
5. Using the Geometry Import Task to Pick Nodes directly from the CAE (or CAD) model and Draw Lines between them Automatically
6. Additional Options on the Geometry, Import Task.
 

1. Where to find Geometry Creation

Either Start Simcenter Testlab Desktop Neo (or any Neo application) and turn on the Geometry Creation add-in (see Figure 1).

Figure 1 - Turning on Geometry Creation add-in.

The Geometry Creation add-in requires 16 tokens.  For more information on tokens, see Simcenter Testlab Tokens: What are they, and how do they work?

The Simcenter Testlab Geometry Creation program can also be started as a standalone application from the Testlab Neo Structures Analysis folder (see Figure 2). 

Figure 2 -  Starting Geometry Creation as a standalone application.

The Geometry Task group in Simcenter Testlab Neo has an Edit Task and an Import Task as shown below.  We will start on the Edit Task.



1. Using the Geometry Edit Task and Home Ribbon to Create Simple Geometries

• Go to the Geometry, Edit Task. On the Home Ribbon you can see that you can add or create new geometries, new components, new nodes, new elements (lines or surfaces), derived DOFS, Discs (Torsional).  You can also add rows and import, export CSV files.  On the left side via the pulldowns you can select the active Section and the Active Geometry.  Simcenter Testlab now supports multiple geometries in the same project with one being the active one.
• Save your project if you have not already done so and it is still called Project 1.

Figure 3 -  The Home ribbon on Geometry, Edit.
 

• Create a new Component via the New Component button on the Organize Geometry part of the Home ribbon.  In the Properties Panel you will see that it was created with Name=Component1, it is using the Cartesian coordinate system by default and you can see the coordinates of its origin.  Change the Component name and color if you wish.  I will create a blue component named Box as shown here.  Note that you may see a different unit for the Coordinate and Euler angles depending on the default settings for length and angle in Simcenter Configuration and Unit system.  If do not like the units shown for length and angle, change their default unit in the Simcenter Testlab Units.

• Select the Box component in the Left Active Geometry panel, Click Add Row (in the Geometry Tables part of the Home ribbon) 8 times to add 8 blank rows and enter the Node coordinates as shown here in Figure 5.  You can right click and Copy / Paste, use CTRL-C and CTRL-V or use Copy and Paste from the Clipboard part of the Home ribbon as needed.  You can also use the square in the bottom left corner of a range to pull down similar to MS Excel.  By selecting rows in the Nodes table you will see the nodes in the Preview Display.

• Add an Euler angle of 45 degrees to Node 1 in the Nodes table by entering 45 degrees in the XY(deg) column as shown in Figure 6.  The Euler angle can be viewed in the Nodes Geometry Table, the Node Properties and the Geometry Preview Display (by right clicking and selecting Deformed Geometry,  Nodes, Euler Angles.  The Node Names and Markers can be turned on here as well).
• Turn on the Node Euler Angles, Node Names and Node Markers as shown in Figure 6.
• Change the Euler Angle back to 0 since we do not need it.

• Verify Lines is turned on the lower left corner State Control Panel and click Add to Add Lines. 

 

• Create the lines as shown in Figure 7 to draw the box.  Double click a node to stop drawing so that you can start a new line elsewhere.  Press Stop in the lower left corner to Stop Drawing Lines.

• Click Elements in the Geometry Tables part of the Home Ribbon to change the Geometry tables from Nodes to Elements.  Elements will show any Lines, Triangles or Quadrilaterals you have Added.
• In the bottom left State Control panel, select Quadrilaterals (instead of Lines) and select Add.  Draw the quadrilateral elements as shown in Figure 8.  Click 4 nodes to complete a quad and then continue onto the next one.  Click the last node twice to stop drawing to start another quadrilateral elsewhere.  Hold down your left mouse button to rotate the geometry as needed.   Hold down the first button in the top left corner of the geometry display and move your mouse to translate or move the geometry (see Figure 8).  Hold down the second button in the top left corner of the geometry display and move your mouse up / down to Scale the Geometry.  If you've enclosed the box you should see the 12 lines and 6 quadrilaterals created in the Elements table as shown in Figure 8. 
• Click Stop to stop adding quadrilaterals elements.

• In the Home Ribbon, switch the Geometry table to view Derived DOFs and then change the State Control Panel to Derived DOFs and press Add as shown in Figure 9.  Add a derived DOF to see how it works.  Derived DOFs are useful to animate a node you cannot measure or you measured and the data was bad.  The Derived DOF can follow one main node or up to four.  A linear interpolation is used between the main nodes, according to the line or plane that connects them. If needed the derived node has first to be projected onto this line or plane.
• Select a node on the Geometry.  The first node you select will be the Derived Node and will turn blue (mine will not because it's already blue!). 
• Select from 1 to 4 Main nodes, turn on their directions in the state control panel and press Add to create the Derived node (See Figure 9).  The main nodes will turn red (if your component is already red you won't know it's doing this).  The Derived DOF and its directions will not show up in the Geometry table until Add is pressed.
• Repeat as needed.
• Click Stop to stop Adding Derived DOFs.  Once stopped you can view the Derived Nodes in the Geometry Table and edit the X, Y, Z derived degrees of freedom if needed.  

• Click Discs in the Geometry Tables part of the Home Ribbon and then Discs and Add in the lower left State Control panel as shown in Figure 10.  Discs are used to animate rotational acceleration, velocity and displacement sensors (or derived or virtual channels) to show twist along a shaft for example.
• Select a Node, select the Direction and then click Add.   The disc will be created such that it's direction is normal to he plane it is drawn in.
• Repeat for a second disc as shown in Figure 10.
• Press Stop when complete.  After pressing stop you can edit the radius of the disc (default is 0.1m) and its orientation.

• Delete the two discs you just created.

• Save the project (to be safe)
• Select the Box component in the Active geometry and then either right click to Delete or press Delete in the Organize part of the Home ribbon as shown in Figure 11.  You get a warning and if you select Yes then everything related to that component is deleted (the component, nodes, elements, derived DOFs and Discs are deleted).
• Click Undo and all deleted items return.

• Select the Box component in the Active Geometry and either right click, select Duplicate or click Duplicate in the Organize Geometry part of the Home ribbon as show in Figure 12.
• Change the name of the component of the new component from Box1 to Box 2 via either right click, rename or selecting Rename in the Organize part of the Home ribbon or via the Properties panel of Box1 as shown in Figure 13.

• Move the Box2 component 2m in the X direction via the Properties panel of component Box2 or via the Move button in the Organize area of the Home ribbon as shown in Figure 14.

• Display the Nodes geometry table of either the Box or Box2 component and click Export CSV.  Call it Nodes.csv.  It will be saved in C:\Simcenter\Testlab Data by default.
• Display the Elements geometry table of the same component and click Export VCSV.  Call it Elements.csv.  It will be saved in C:\Simcenter\Testlab Data by default.
• Create a New component and call it Box3 with a different color.
• Select the Box3 from the active geometry, select the Nodes Geometry table and select Import CSV to import Nodes.csv
• Select the Box3 from the active geometry, select the Elements Geometry table and select Import CSV to import Elements.csv.
• Move the Box3 component 4m in X if created from Box or 2m in X if created from Box2.  You should have 3 boxes as shown in Figure 15.  If you select a component you will see its color and that is the one you are currently editing.  The others will be transparent as shown in Figure 15.  If you cannot see all 3 boxes, right click in the display and select "Fit Model."

• Add Lines between the 3 components.  Do you see these elements when looking at the Box, Box2, or Box3 component or just when looking at the Elements in the Geometry?
• View the Elements geometry table and select the Box, Box2 and Box3 component and then the Geometry1 feature to see the difference.  You will only see lines between components when viewing the geometry feature and not the components.

• Create a new Geometry.  By default the geometry is named Geometry2 and the active Geometry pulldown has switched to Geometry2 as shown in Figure 16.  You can change the name of the Geometry by right clicking on it and selecting rename, or clicking Rename in the Organize part of the Home ribbon or by changing the name of the Properties panel when the Geometry is selected.  We now have 2 geometries in this project with one active as shown via the active geometry pull down.
   

• Go to the Add ribbon and select to add a Rectangle.  Create the rectangle with component name Rect1 in the Global XY plane, Length of 2 m with 4 nodes along length, width of 4m with 8 nodes along width and turn on Meshing, create lines and surfaces as shown in Figure 17.  After creation, change the color of the Rect1 component if you wish via the Rect1 Properties pane.  You could also move or rotate it if you wish via this Properties pane.

• Add another Rectangle but change the Plane to Global YZ as shown in Figure 18.  See the Euler angles that are added.  If you do not want these Euler angles, you can remove them on the Rect2 Properties panel under the Home ribbon as shown in Figure 19.

• Go to the Add Ribbon and add a Prism as shown in Figure 21.  A Prism is basically a Cube or Box that could have different area base and top.  Here I have hidden Rect1 and Rect2 via Component Visualisation.  

• Create a 3rd Geometry for the next part. 
• Add a few Circles to investigate the effects of Circular Mesh, Radial Mesh, Add node in the center and Nodal axis system as shown in Figure 21.  You can use the Component Properties pane to shift each component along X as shown below (and in Figure15).

• Undo and Redo a few times to remove the circles and bring them back.
• Now Add a cylinder to see how that works as shown in Figure 22.  Investigate the effect of Nodal Axis system and Add node in the center.  If you don't like result, click Undo and try again.

• Create another Geometry and a New Component under it.
• Use Import CSV to import the 8 nodes we saved earlier as shown in Figure 24.

• Go to the Add Ribbon and select Autowire. Investigate the effects of Use All Nodes, Use Selected Nodes, Min angle between wires, Max number of wires per node and Max Distance Ratio.  Use Undo as needed.

• Save your existing Testlab project via File, Save.
• Open a new project via File, New and select the Blank Project template to be used. 
• Save the new project with a useful name other than Project1, Project2, etc.
• Browse to a CAE file (or CAD), expand it so that you see the Geometry icon and then either click Import in the Home ribbon, Organize Geometry area or right click and select Import.  Choose the defaults to Create a new Geometry.  The plane Nastran file shown here has about 20,000 nodes.  After Import you should see the imported geometry in the Preview Display and also the Active (Geometry) Display as shown in Figure 26.  We might want the full geometry imported for use later in Mode Shape Expansion for example.

• Select the CAE geometry again and select to use Automatic Reduction from the Home Ribbon in the Organize Geometry area or via right click on the Geometry as shown in Figure 28.  Provide a Geometry name, maximum number of nodes, choose a symmetry pane and if you have modes available in the same file or in the Input basket the mode shapes can be reduced as well.   

• Make sure the Active Geometry is the Reduced one via the Active Geometry pull down in the Organize part of the Home Ribbon.
• Go to the Geometry, Edit Task and from the Add Ribbon select Autowire.  Try out different settings by using Apply and Undo as needed as shown in Figure 29.  Undo as needed selecting either a better Autowire or a better Automatic Reduction.  You could also delete the Geometry (if it is not the active geometry) and try again.

• Create a new geometry and make sure it is the active one.  I've called mine Frame here and I am going to use an ANSYS *.rst file this time.
• In the Geometry, Import task click the Pick Nodes action from the State Control panel in the lower left corner as shown in Figure 30.
• If you want to Connect the Nodes while you are picking them, turn that option on.

• Pick some nodes from your CAE or CAD geometry in the Preview Display and turn on Connect Nodes.
• In the Active Geometry display select Fit Model to zoom in and also turn on Node Markers and Lines under Deformed Model if you do not see them.
• In the Test Node Picking Property panel there are also options to rename nodes and reduce the mode set if desired.  As stated earlier, one advantage to not renaming the nodes is that the Test Geometry nodes will exactly match your CAE model so you can easily do a MAC between the TEST and CAE common nodes since the node IDs match.  If you start adding component names and renumber the nodes, this may be convenient for the Test Engineer or Technician but then becomes more difficult to correlate TEST and CAE in Testlab.  An external tool like Simcenter 3D Correlation could be used in that case.

• Stop picking Nodes and return to the Geometry, Edit task to finish your geometry.

• On the Geometry, Import task in the Home Ribbon try the different options in the Display area.  You can change the Active and Preview displays from Single to Quad and also Link the views so if rotate one display they both rotate.