Tutorial: Connecting Parts with Spot Welds

Create and use spot welds to connect multiple surface parts.

In this lesson you will learn how to:
  • Use spot welds to connect multiple surface parts
  • Create spot welds at predefined points and other locations.
  • Define the weld diameter
  • Change the search distance
  • Run an analysis

    Spot welding is a common method of joining surface parts. Spot welds can be created either at predefined points, or simply by clicking on a location. When creating a spot weld, you need to define the weld diameter and which parts are being connected. Surface parts that lie within the search distance are automatically included in the spot weld, and individual parts can also be added or removed manually.

    This tutorial uses a simple assembly with three surface parts and three points. The desired spot weld locations are often defined using a CAD system and then imported into Inspire, but they can also be defined in Inspire itself. The model includes predefined loads and is nearly ready to run. All that is required is to connect two parts with spot welds at one location and to connect three parts with spot welds at a second location before running the analysis.

Open the Model and Select the Unit System

  1. Press F7 to open the Demo Browser.
  2. Double-click the spotweld.stmod file to load it in the modeling window.
  3. Make sure the display units in the Unit System Selector are set to MPA (mm t N s).

Create Spot Welds at Predefined Points

Create spot welds at the predefined points imported with the model.

  1. Select the Spot Welds tool on the Structure ribbon.
  2. Click the icon on the guide bar and change the Search Distance to 1 mm.
  3. Box select the three points on the model. Note that no spot welds are created. This is because the neighboring parts are not within the 1 mm search distance.
  4. Change the Search Distance to 5 mm and box select the points. This time, spot welds are created between two of the surface parts.
  5. Press Ctrl+Z to undo.
  6. Change the Search Distance to 15 mm and box select the points. This time, spot welds are created between all three of the surface parts.

Create Spot Welds on a Surface Part

Create spot welds by clicking any location on a surface part. The weld is projected normal to the surface, and adjacent parts within the search tolerance are included in the weld.

  1. Change the Search Distance to 5 mm.
  2. Left-click at the three locations shown below to create spot welds:
  3. Press F2 to open the Model Browser. Note that all of the spot welds have been placed into a spot weld group.
  4. You can select welds in the group individually, or several at once by holding the Ctrl key.
  5. Change the Weld Diameter to 6 mm. This updates the diameter for all of the selected welds.
  6. Right-click and mouse through the check mark to exit, or double-right-click.

Create Sketch Points as Weld Locations

Create sketch points to gain more precise control over where spot welds are placed.

  1. Select the Points tool from the Points/Lines icon on the Geometry ribbon.
  2. Select the face on the bottom part (that is parallel to the Top part) as the sketch plane.
  3. Click to place three sketch points as shown.
  4. Select the Transfer Sketch from the sketching toolbar to transfer the three points to a new part. This keeps the weld locations independent of the geometry.
  5. Double-right-click to exit sketch editing mode.
  6. Rename the part as Weld Location Points 2 in the Model Browser.

Create Spot Welds at the New Locations

In the Model Browser, select a part that contains only points to quickly create spot welds at those points.

  1. Select the Spot Welds tool on the Structure ribbon.
  2. Click the icon on the guide bar and change the Search Distance to 10 mm.
  3. Select the Weld Locations Points 2 part in the Model Browser. The spot welds are automatically created.
  4. Right-click and mouse through the check mark to exit, or double-right-click.
  5. Press A twice to hide and then show everything in the model.

Run an Analysis

  1. Click Run Analysis on the Analyze icon on the Structure ribbon.
  2. Run the analysis again using the settings shown below. Set the Element Size to 5 mm, change the Speed/Accuracy to Faster, and set contacts to Sliding only.
  3. Click Run.
  4. When the run is complete, select the run in the Run Status window and click View Now to view the results.
  5. In the Analysis Explorer, select von Mises Stress for the Result Type.
  6. Set the maximum value in the legend to 90 MPa. Note the stress concentrations around the spot welds as expected.