SS-T: 4000 Static Structural Analysis, Pullup Bar

Perform a static structural analysis of a pullup bar assembly.

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:
  • Learn how SimSolid works
  • Create a comparison for SimSolid's workflow and results with those obtained with traditional FEA.
Model Description
There are two different pullup bar models used in this tutorial. Each model has 33 parts. You will perform two static structural analyses for the following:
  • 2 load cases of 750N (168 lbf) total load on different handle locations
  • 2 different design configurations with varying support brackets
The following model files are needed for this tutorial:
  • Pullup bar V1.x_t
  • Pullup bar V2.x_t
Figure 1.

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 Pullup bar V1.x_t.
  4. Click Open.
    The assembly will load in the modeling window. An Info window will appear warning that overlapping parts were detected. The Review overlapping parts dialog will also open.
  5. Close the Info window, then Close the Review overlapping parts window.

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.

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.

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 Support

  1. In the Analysis Workbench, click (Immovable support).


    Figure 4.
  2. In the dialog, verify the Faces radio button is selected.
  3. In the modeling window, select the two faces shown in orange in Figure 5.


    Figure 5.
  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 Loads

  1. In the Analysis Workbench, click (Force/Displacement).


    Figure 6.
  2. In the dialog, ensure the Faces radio button is selected.
  3. In the modeling window, select the two handle faces shown in orange in Figure 7.


    Figure 7.
  4. Specify a Z direction force of -750 N.
  5. Click OK.
    The new force, Load/Displ. 1, appears in the Project Tree. Vectors representing the load are shown on the model.

Create Second Structural Linear Analysis

  1. In the Project Tree, right-click on Structural 1.
  2. Choose Copy from the context menu.
    The Structural 2 analysis appears in the Project Tree.


    Figure 8.
  3. Click next to Structural 2 to expand the analysis branch.
  4. Edit the handlebar loads.
    1. Double-click on the Load/Displ. 1 load under Structural 2.


      Figure 9.
    2. In the Force/Displacement dialog, select the faces currently listed and pick Delete.
    3. In the modeling window, choose the two front handle faces.


      Figure 10.
    4. Click OK.
      Vectors representing the load are shown on the model.


      Figure 11. Load case 1


      Figure 12. Load case 2

Run Design Study

Solve all analyses in the design study.

  1. In the Project Tree, click the desired Design study branch.
  2. Click (Solve).
    SimSolid runs all analyses in the design study branch. When finished, a Results branch for each analysis appears in the Project Tree.

Compare Results with Bookmarks

  1. In the Project Tree, select the Results branch for Analysis 1.
  2. On theAnalysis Workbench, click (Results plot).
  3. Select the Displacement Magnitude plot.
  4. In the Legend window, click (Show deformed shape).
    The modeling window updates to show the chosen results and display options.
  5. Click the (Snap bookmark) icon.
    SimSolid saves the data currently displayed in the modeling window as an image or animation, and a thumbnail appears in the Bookmark browser. You can select a bookmark at any tine to display a saved view in the modeling window.


    Figure 13.
  6. Repeat steps 1 through 5 for Analysis 2.
  7. Toggle between the different results using the Bookmark browser.

Create Second Design Study

The new geometry is almost identical to that of Study 1. The only difference is the design of the vertical support brackets. SimSolid instances identical geometry to minimize resources required; this makes the database smaller and the solutions faster.

Repeat the Import Geometry step and load the file Pullup bar V2.x_t.
The new geometry is read into a second design study. All analysis definitions are copied from Study 1 to Study 2. Conflicts and inconsistencies are flagged in red in the Project Tree. This tutorial does not require you to fix geometric inconsistencies.


Figure 14.
Note: New parts in the assembly do not yet have materials assigned.


Figure 15. Design Study 1


Figure 16. Design Study 2

Add Connections for New Parts

  1. Close the part overlap warning and review dialog.
  2. In the Add connections for new parts dialog, specify gap and penetration tolerances as 1.
  3. For Connection resolution, select Increased.
  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 Design Study

Solve all analyses in the design study.

  1. In the Project Tree, click the desired Design study branch.
  2. Click (Solve).
    SimSolid runs all analyses in the design study branch. When finished, a Results branch for each analysis appears in the Project Tree.

Compare Results

  1. In the Bookmark browser, click a thumbnail to load a saved results view.
  2. In the Project Tree, click on any Results branch.
    The modeling window updates with the results from the chosen analysis. You can click on other Results branches to rapidly switch between views.

View Reaction Forces

  1. In the Project Tree, open the Analysis Workbench.
  2. In the workbench toolbar, click the (Reaction/contact force) icon.
  3. Click the Supports, Connections, or Parts tab.
    A summary table of the reactions opens. Moment vectors are displayed in the modeling window.


    Figure 17.
  4. Optional: Select a single support, connection, or part to view forces on a single element.
  5. Optional: Select multiple supports, connections, or parts to view a summary of forces.

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

Refine Solution Settings

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


    Figure 18.
  5. In the Project Tree, select the Project.
  6. Click (Solve).
  7. Examine the changes in results.
  8. Compare with Pass 3 results.
    1. In the Analysis Workbench, select > Von Mises Stress.
    2. In the Legend, in the box under Max, enter 80.
      This adjusts (locks) the legend to be similar to a 3 pass solution to better highlight peak stress areas.
    3. Click to reset the legend to default values.


      Figure 19.