Advanced Results Processing

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Advanced Results Processing

• Workshop 8

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Workshop 8 - Goals

• In this workshop a high pressure vent assembly is
  analyzed for stress and deflection.
• Some of the results from the analysis will be
  difficult to interpret if all bodies are active
  during postprocessing. Our goal is to isolate
  parts of the model and use some of the advanced
  DS features for postprocessing.

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Workshop 8 - Assumptions

• We will assume that gas is being vented through
  the inlet pipe into the expansion chamber.
  Inside the chamber the pressure drops to 20 of
  the inlet pressure.
• The expansion chamber is rigidly mounted to the
  inlet thus we will leave this contact region
  defined as bonded.
• The support bracket allows limited movement to
  the pipe so no separation contact will be used
  here.
• See the contact description on the next page.
• The inlet pipe and bracket are modeled using
  structural steel while the expansion chamber is
  polyethylene.

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Workshop 8 Part/Contact Description
Expansion Chamber
Bonded Contact
Support Bracket
No Separation Contact
Inlet Pipe
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Workshop 8 - Start Page

• From the launcher start Simulation.
• Choose Geometry gt From File . . . and browse
  to the file Pressure system.x_t.
• When DS starts, close the Template menu by
  clicking the X in the corner of the window.

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Workshop 8 - Preprocessing

• Set the working units to Metric (mm).
• Units gt Metric (mm, kg, MPa, C, s).
• Change the bracket/pipe contact type to no
  separation
• Highlight the Contact Region 2 branch.
• In the detail window change the contact type to
  No Separation.

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. . . Workshop 8 Preprocessing

• Change the material for the expansion chamber to
  polyethylene.
• Highlight the part in the tree.
• In the detail window click in the material field
  and Import . . . gt Polyethylene.

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Workshop 8 - Environment

• Apply pressure to the inside surfaces of the
  pipe
• Highlight the Environment branch.
• Select the 5 interior surfaces of the pipe (use
  Extend select).
• RMB gt Insert gt Pressure.

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. . . Workshop 8 - Environment

• In the detail window for the pressure enter 1 in
  the magnitude field (1 MPa).

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. . . Workshop 8 - Environment

• Select the 3 interior surfaces of the expansion
  chamber.
• Note, using the selection planes, the status bar
  and the CTRL key will simplify this selection.
• Alternately use RMB gt Hide All Other Bodies

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Status Bar
Selection planes
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. . . Workshop 8 - Environment

• RMB gt Insert gt Pressure.
• In the detail window change the magnitude to 0.2
  MPa.
• Select the end surface of the pipe.
• RMB gt Insert gt Fixed Support.

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. . . Workshop 8 - Environment

1. Select the surface of the cylinder in the
   bracket.
2. RMB gt Insert gt Cylindrical Support (leave
   default fixed,fixed,fixed).

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. . . Workshop 8 - Environment

• Select the back face of the bracket.
• RMB gt Insert gt Frictionless Support.

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Workshop 8 - Solution

• Highlight the solution branch.
• RMB gt Insert gt Stress gt Equivalent (von Mises)
• RMB gt Insert gt Deformation gt Total
• Solve

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Workshop 8 - Results

• When the solution is complete (OK the weak
  springs message), highlight the 2 result objects
  and view them. Notice the total deformation plot
  contains very little detail for the inlet pipe
  and support bracket parts of the assembly.

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. . . Workshop 8 - Results

• Scope a new total deformation to the expansion
  chamber
• Highlight the solution branch.
• Switch to body select mode and highlight the
  expansion chamber in the graphics window.
• RMB gt Insert gt Deformation gt Total.

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. . . Workshop 8 - Results

• Repeat the procedure on the previous page but
  choose Equivalent stress as the result.
• Repeat the procedure on the previous page and
  above for the remaining parts.
• Solve again to update the new result objects.
• Compare the overall result to the individual ones
  (as shown below). Note the increased detail
  shown in the individual plots.

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. . . Workshop 8 - Results

• Add a slice plane.
• Plot the stress scoped to the expansion chamber
  then reorient the model to look into the Z axis
  as shown below.
• Note the triad at the bottom of the screen can be
  convenient to reorient the model.
• Click on the slice plane icon and hold down the
  left mouse button and draw a line down the center
  of the plot.

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. . . Workshop 8 - Results

• In order to see the sliced plane you will need to
  rotate the model slightly (when first drawn) you
  are looking at the edge.

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. . . Workshop 8 - Results

• To edit a slice plane first click on the Edit
  Planes icon.
• A handle will appear in the graphics window.
  Using the left mouse button you can click and
  drag the slice plane to a new location.

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. . . Workshop 8 - Results

• By clicking on one of the dashed lines on either
  end of the handle you can activate the result
  plot on one side of the slice plane. Note the
  dashed line then becomes solid. This is a toggle
  control.

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Workshop 8 Slice Plane Notes

• You may create as many slice planes as desired
  and each can be edited individually. This can be
  useful for things like plotting a quarter section
  of a result.
• Note, use the Tab key to toggle between defined
  slice planes to modify each
• To hide the slice plane(s) use the drop down
  geometry type icon and return to an exterior
  plot. The slice plane(s) remains in its current
  location and can be reactivated whenever desired.
• Figures which contain slice planes will display
  slice planes regardless of the setting of the
  geometry icon.

Geometry Icon
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. . . Workshop 8 - Results

• Change the plot type from slice planes to
  exterior and plot the result for the support
  bracket.
• Change to the IsoSurfaces display type.

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. . . Workshop 8 - Results

• Change to the capped isosurface display type.
• By clicking in the legend and dragging the slider
  the capping point can be modified.

Drag
Drag
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. . . Workshop 8 - Results

• Reactivate the exterior plot for the complete
  assembly stresses.
• From the Edges icon choose to Show Elements.

Edges Icon
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. . . Workshop 8 - Results

• Finally add some annotations to pin point
  results.
• Plot the exterior stress plot for the assembly.
• Activate the Probe and click several locations
  on the model to add annotations.
• Note to remove annotations activate the Label
  icon and highlight the specific annotation. Use
  the keyboard delete key to remove the
  annotation.