SS-T: 3000 Non-linear Separating Contact and Bolt Pretensioning, Hanger Beam

Perform non-linear separating contact analysis and setup bolt/nut tightening loads.

Prerequisites
Some features used in this tutorial are only available in SimSolid Advanced version. Please switch to Advanced to complete this tutorial.
Purpose
SimSolid performs meshless structural analysis that works on full featured parts and assemblies, is tolerant of geometric imperfections, and runs in seconds to minutes. In this tutorial, you will do the following:
  • Perform assembly analysis
  • Perform non-linear separating contact analysis
  • Use SimSolid bolt tensioning functions
  • Compare SimSolid results with those obtained in traditional FEA.
Model Description
The hanger beam model in this tutorial has 70 parts, 16 bolts/nuts, and 32 washers.


Figure 1.
The following files are needed in this tutorial:
  • Hanger beam.x_t (CAD source file)
  • Hanger Beam.ssp (SimSolid project files with the first load case solved. This is where you start the tutorial.)
  • Hanger Beam SOLVED.ssp (SimSolid project file with all load cases solved. Provided as a reference.)
Important: The introductory steps of this tutorial provide information on how the first analysis was created. If you wish to skip this, go straight to Open Project.

Import Geometry

  1. Open a new SimSolid session.
  2. Click the (Import from file) icon.


    Figure 2.
  3. In the Open geometry files dialog, choose Hanger Beam.x_t.
  4. Click Open.
    The assembly will load in the modeling window. The Automatic connections dialog opens.

Create Connections

  1. In the Project Tree, click on the Connections branch.
  2. In the Connections workbench toolbar, click (Automatic connections).
  3. Specify Gap and Penetration tolerances as 1.
  4. Set Connection resolution level to Increased.
  5. Click OK.
    Note:
    • SimSolid creates connections even in areas with overlapping geometry.
    • SimSolid automatically identifies bolts, nuts and washers.
    • Sliding contact is applied automatically in bolt shanks, bonded is applied otherwise.

Create Structural Linear Analysis

  1. On the main window toolbar, click (Structural analysis).
  2. Choose Structural linear.


    Figure 3.
    The new analysis appears in the Project Tree under Design study 1 and the Analysis Workbench opens.

Create Immovable Supports

  1. In the Analysis Workbench, click (Immovable support).
  2. In the dialog, verify the Faces radio button is selected.
  3. In the modeling window, select the faces shown in Figure 4.


    Figure 4.
  4. Click OK.
    The new constraint, Immovable 1, appears in the Project Tree. A visual representation of the constraint is shown on the model.

Create Force

  1. In the Analysis Workbench, click (Force/Displacement).
  2. In the dialog, ensure the Faces radio button is selected.
  3. In the modeling window select the faces shown in Figure 5.


    Figure 5.
  4. Specify a Z direction force of -1000 N.
  5. Click OK.
    The new force, Load/Displ. 1, appears in the Project Tree. Vectors representing the load are shown on the model.

Change Max Number of Adaptive Solutions

  1. In the Project Tree, double-click on Solution settings.
  2. In the dialog, set the objective to Custom and increase the number of adaptive solutions to 4.
  3. Select the Adapt to features check box.
  4. Click OK.

Assign Materials

  1. In the Project Tree, click on the Assembly branch.
  2. In the Assembly workbench, click (Apply materials).
  3. Pick Steel from the Generic materials list.
  4. Click Apply to all parts.
  5. Click Close.
    In the Assembly branch of the Project Tree, material properties are identified for each part.

Run Analysis

  1. In the Project Tree, open the Analysis Workbench.
  2. Click (Solve).

Open Project

  1. Start a new SimSolid session.
  2. Click the (Open Project) icon.


    Figure 6.
  3. In the Open project file dialog, choose Hanger Beam.ssp
  4. Click OK.

Create Non-linear Separating Contact Analysis

  1. In the Project Tree, right-click Structural 1 and choose Copy.
    The copy will appear as Structural 2 in the Project Tree.
  2. Under Structural 2, right-click on Setup and choose Edit.


    Figure 7.
  3. In the dialog, select the Separating contact check box.


    Figure 8.
  4. Click OK.

Edit Contact Conditions

  1. In the Bookmark browser, click Bookmark 5.


    Figure 9.
    The modeling window updates with the saved view.
  2. In the modeling window, right-click on the Hanger beam (shown in orange) and select Review part contact conditions.


    Figure 10.
  3. In the dialog, hold down Control and click to select Connection 120 and Connection 121.
  4. Click the Edit contact conditions button.


    Figure 11.
  5. In the Contact conditions dialog, select Structural 2.
  6. Activate the Separating radio button.


    Figure 12.
  7. For the Friction coefficient, specify 0.1.
  8. Click Close.

Run Analysis

  1. In the Project Tree, open the Analysis Workbench.
  2. Click (Solve).

Compare Results

  1. In the Project Tree, select the Structural 1 branch.
  2. In the Bookmark browser, choose Bookmark 3.
    This bookmark shows the deformation detail.


    Figure 13.
  3. In the Project Tree, select the Structural 3 branch.
    The modeling window updates to show deformation detail for Structural 2.
  4. Optional: Switch back and forth between Analysis branches to highlight the differences in the results.
  5. Repeat steps 1 through 4 for Bookmark 4 (stress detail).


    Figure 14.

View Separation and Contact Forces

These forces are represented as colored values at each connection point (not a true contour). You used increased resolution when creating connections to get a denser array of points to plot.

  1. In the Project Tree, select the Results branch under Structural 2.
  2. On the Analysis Workbench, select (Contact Response).


    Figure 15.
  3. In the Response at connections dialog, hold down Control and click to select Connection 120 and Connection 121.
  4. Select the response type you wish to view.
  5. Use the slider to increase or decrease the size of the colored points.


    Figure 16.
  6. Click Close.

Setup Bolt/Nut Tightening

  1. In the Project Tree, right-click on Structural 2 and select Copy.
    The copy appears as Structural 3 in the Project Tree.


    Figure 17.
  2. In the Bookmark browser, select Bookmark 5 (Bolted joint).
  3. Verify Structural 3 is selected in the Project Tree.
  4. In the Analysis Workbench toolbar, click (Nut tightening) .
  5. In the modeling window, select the 4 nuts attached to the hanger beam as shown in Figure 18.


    Figure 18.
  6. For Thread pitch, enter 1 mm.
  7. Activate the Target axial load radio button and enter 5000 N.
  8. Click OK.

Run Analysis

  1. In the Project Tree, open the Analysis Workbench.
  2. Click (Solve).

Compare Results

  1. In the Project Tree, select the Structural 1 branch.
  2. In the Bookmark browser, choose Bookmark 3.
    This bookmark shows the deformation detail.


    Figure 19.
  3. In the Project Tree, select the Structural 3 branch.
    The modeling window updates to show deformation detail for Structural 2.
  4. Optional: Switch back and forth between Analysis branches to highlight the differences in the results.
  5. Repeat steps 1 through 4 for Bookmark 4 (stress detail).


    Figure 20.

Compare with Traditional FEA

  1. Use the model files to run this same analysis with your traditional FEA application.
    Important:
    • Do not merge or simplify geometry, use bonded and sliding contact same as SimSolid.
    • Check for part overlaps
    • Make sure element density is acceptable for smaller parts
  2. Compare the following between the two programs:
    • Solution quality
    • Number of workflow steps required
    • Time required to mesh
    • Time required to solve
    • Time required to examine results
    • Time required to refine and rerun model