Tutorial: Running a Baseline Analysis

Run a baseline static analysis, then review and animate the results.

In this lesson you will learn how to:
  • Run a baseline static analysis
  • View results for the factor of safety
  • View results for displacement
  • View results for von Mises stress
  • View results for tension and compression
  • Play an animation


Overview

In this tutorial, you will run a baseline static analysis of a part in a steady state and review the results.

In mechanics we define a steady state as the state of a system that is in equilibrium. Equilibrium means the loading in the system is balanced so that the system remains at rest (V=0). This equilibrium system is called static analysis. When solving a static analysis, all finite element solvers will solve the equation Kx = f where:
  • K: is the global stiffness matrix
  • x: is the displacement vector response to be determined
  • f: is the external forces vector applied to the structure

The following tutorial demonstrates how to run a baseline analysis in order to better understand what a static analysis is.

Open the Baseline Analysis Model

  1. Press F7 to open the Demo Browser.
  2. Double-click the Baseline Analysis.stmod file to load it in the modeling window.


  3. If not already visible, press F2 to open the Model Browser.


  4. Make sure the display units in the Unit System Selector are set to MPA (mm t N s).

Run a Baseline Static Analysis

  1. Select the Structure tab on the ribbon.
  2. Click Run Analysis on the Analyze icon to open the Run Analysis window.
  3. Change the Element size to 3 mm.


  4. Make sure that Speed/Accuracy is set to More accurate.


  5. Click Load Cases and verify that both the Jump and the Rock load cases are selected.


  6. Click Run to perform the analysis.
    The Run Status window appears. A green check mark will appear when the analysis is complete. (This may take several minutes.)


  7. Double-click on the name of the run to view the results.
    The results are displayed in the Analysis Explorer.


View the Factor of Safety Results

  1. In the Analysis Explorer under Show, click the icon and select Hide all loads and supports.
  2. The factor of safety result type for the Rock load case is shown in the modeling window.
    By default, areas that are approaching a minimum safety factor of 1.0 are shown in red to indicate where the part is most likely to fail. Since the model is all blue, the part is not in danger of failing for this load case.


  3. In the Analysis Explorer under Load Case, select the Jump load case.
    The areas shown in pink indicate where the model is under stress.


  4. In the Analysis Explorer under Factor of Safety, click and drag the slider on the legend until the model just disappears.
    This masks all areas on the model with a factor of safety higher than the selected value on the slider.


  5. The factor of safety is around 1.4. Since this is greater than 1.0, the model is not predicted to fail for this load case.


View the Displacements Results

  1. In the Analysis Explorer under Result Type, select Displacement.


  2. The maximum displacement for the model is approximately .4 mm, as shown in the legend.


  3. Click the Show/hide deformed state icon to show the deformed state of the model. Click the icon again to hide it.


  4. Click the button under Animation to visualize the displacement.
  5. Click the button and use the slider to change the speed of the animation.
  6. Inspire automatically scales the displacement animation to make it easier to see. Click the button, deselect Auto, and enter a value to change the scale of the animation.
  7. Click the button to stop the animation.

View the von Mises Stress Results

  1. With the Jump load case still selected, switch to von Mises Stress for the Result Type.


  2. By default, the peak stress for the load case is shown. Click the button next to the legend in the Analysis Explorer and select Aluminum.


  3. The majority of the rocker arm is blue, but the pin is red. However, the pin is made of titanium, not aluminum.


  4. Click the button next to the legend in the Analysis Explorer and select Titanium.


    Now the pin is blue as well. It's looking good!

View the Tension and Compression Results

  1. Last but not least, select Tension and Compression under Result Type.
    Areas on the model shown in orange are subject to tension, and areas shown in green are subject to compression.


  2. Click the Show/hide the initial shape icon to show and hide the initial shape as a reference.
  3. Click the Show/hide the contours icon to show and hide the contours. Use the Contour options button to turn off blended contours or interpolate during animation.
  4. If you want to change the legend colors used for this or any other result type, click the Legend options button next to the legend and select Legend Colors. This will open the Preferences window, where you can change the default legend colors for each result type.
  5. When finished, close the Preferences window and the Analysis Explorer.