Activity 6: Compare the study results

In this activity, you perform a side-by-side comparison of the results of Study 1 and Study 2. The Compare tab enables you to view the results of up to four simulation studies, at the same time, in tiled windows. To compare the results of the two studies, you

compare x-displacement

Study 1: Displacement in a statically stable model (left), and Study 2: Displacement in a partially unconstrained model (right).

Important: Slight differences in the generated mesh or the contact iterations are not uncommon from release to release of the software or even when the model is solved on different computer platforms. Your results should be similar to those shown on this page. However, they may not necessarily be identical. You can disregard minor differences in the results.

Prerequisties

Steps

  1. Access the Compare tab and select the studies to compare.

    1. Click compare icon (Simulation workspace > Results tab > Compare panel > Compare), to access the Compare dialog.

      Two side-by-side contour plots appear.
    2. Check the names of the results in the lower-left corner of each window, and confirm that you see a result from study 1 and one from study 2.

      Typically, Study 1 appears in the left window, and Study 2 appears in the right window, which is what you want.
    3. If necessary, use the drop-down menu, next to the study name, to select a different study to display.

      Note: The results options, study selector, ViewCube, and Navigation Toolbar are only visible for the active window. Click anywhere within a Compare window to activate it.

  2. Synchronize the Camera, so the model moves in both windows in the same manner, and the Result Type so that switching result in one window changes the other window to the same result.

    1. Click synchronize camera icon (Simulation workspace > Compare tab > Synchronize panel > Synchronize Camera), to synchronize the view of the models in the two windows.

      The icon on the ribbon turns blue to indicate that it is active.
    2. Click synchronize result type icon (Simulation workspace > Compare tab > Synchronize panel > Synchronize Result Type), so that when you switch the result in one window, the result changes in the other window, automatically.

      The icon on the ribbon turns blue to indicate that it is active.

  3. Switch to the Displacement result and compare the X-displacement in Study 1 with Study 2.

    1. Click in the left window to activate it.
    2. Using the drop-down menu near the plot legend, set the displayed result to Displacement.
    3. Using the drop-down menu near the plot legend, change the direction from Total to X.

      The X displacements appear in both windows.

      compare x-displacement

      Observations
      • Because one end of the Study 1 model is fixed, and the force stretches the assembly in the -X direction, all X displacement results are negative.
      • For Study 1, the maximum relative X displacement magnitude for the assembly is about 0.0035 in.
      • Since the Study 2 model is being acted on by +X and -X forces, positive and negative X displacement results are evident. The zero-displacement area is near the middle of the connecting rod span.
      • The displacement variation for Study 2 is 0.00264 in to about - 0.00154 in. Therefore, the maximum relative displacement for the assembly is 0.0026 - (-0.00154 in), or approximately 0.0042 in.
      • The deformation of the assembly is greater in Study 2, which is not surprising. The small pin is free to bend more without the fixed constraints on the end faces.

  4. Switch to the Stress result and compare the von Mises stresses in Study 1 with Study 2.

    1. Using the drop-down menu near the plot legend, change the result type from Displacement to Stress.

      The von Mises stresses appear in both windows.

      compare von Mises

      Observations
      • The maximum von Mises stress for Study 1 is between 21,600 and 21,700 psi. The location, as we saw previously, is at the edge of the short pin. This pin behaves as a built-in beam, where the greatest moment occurs at the end supports.
      • The maximum von Mises stress for Study 2 is approximately 24,300 psi. It occurs on the surface of the small pin at its mid-length.

        Tip: If desired, you can temporarily return to the Results tab to hide parts and to show the Min/Max probes, which are not available in the Compare tab. Do this to locate the maximum result when it is located on hidden faces.
      • The Study 2 stress exceeds the Study 1 stress by approximately 12%.

  5. Switch to the Safety Factor result and compare Study 1 with Study 2.

    1. Using the drop-down menu near the plot legend, change the result type from Stress to Safety Factor.



      compare safety factor

      Observations
      • The safety factor results reflect the increased stress level in Study 2, where the safety factor is 25% lower than that of Study 1.

  6. Switch to the Contact Pressure result and compare Study 1 with Study 2.

    1. Using the drop-down menu near the plot legend, change the result type from Safety Factor to Contact Pressure.

      compare contact pressure

      Observations
      • The greater amount of small pin bending deflection in Study 2 results in a more localized contact area near the edges of the connecting rod hole. The end result is an 33% increase in contact pressure for Study 2, which is not surprising.

Activity 6 summary

In this activity, you

Parent page: Tutorial: Static stress analysis
Previous page: Activity 5: Create and run a second study with different loads and constraints
Next page: Tutorial conclusion: Static stress analysis