SS-T: 5030 Linearized Stress

Calculate linearized stress.

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:
  • Calculate linearized stress along a line segment.

Model Description

The following model file is needed for this tutorial:
  • LinearizedStress.ssp


Figure 1.
This file has the following specifications:
  • Material is set to Steel for all parts.
  • Regular connections with 1mm gap and penetration tolerance.
  • Linear static subcase with pressure load and constraints, solution settings set to Adapt for stiffness.

Open Project

Open the SimSolid project file.

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


    Figure 2.
  3. In the Open project file dialog, choose LinearizedStress.ssp
  4. Click OK.

Review Model

Review the model and load case, and plot stresses.

  1. In the Project Tree, expand the Structural 1 Analysis Workbench.
  2. Expand the Loads&Constraints branch and review the loads.
  3. Click (Results plot) and choose the desired plot to review regions of high stress.

Method 1: Line Segment Normal to Surface

Calculate linearized stress on a line segment drawn normal to surface.

  1. For Structural 1, on the Analysis Workbench select (Pick info).
  2. In the dialog, select the Linearized stress tab.
  3. Review the default Failure criteria.
    • Defaults for failure criteria are calculated based on the Yield stress of the material assigned in the project. Membrane stress = 2/3 of Yield stress, Membrane + bending stress = Yield stress, Peak stress = 2x Yield stress.
    • When multiple materials are present in the project, the material with the highest yield stress is used to calculate the default.
    • You can edit these values before or after the linearized stress calculation.
  4. Draw the line segment normal to surface.
    1. Ensure the Normal to surface radio button is selected.
    2. Select the point of interest in the modeling window.


      Figure 3.
      • SimSolid launches a ray that is normal to the surface and passes through the part.
      • A local coordinate system is created with the X axis along the segment.
      • Entry and exit coordinates of the segment are listed in the dialog.
      • Linearized stress along the local coordinate system is calculated for the segment and the values are listed in the dialog. By default, invariants are listed.
      • The Status will show "Passed" as long as the invariants are below the failure criteria.
  5. Select the Show linearized stress tensor components check box to view the stress tensor components.

Method 2: Line Segment on Custom Location

Calculate linearized stress on a line segment drawn at a custom location.

  1. In the Bookmark browser, click Bookmark 1.


    Figure 4.
    Stress vonMises is plotted and the model is oriented with max vonMises location in view.
  2. On the main window toolbar, click (Clip assembly with plane).
  3. On the model, press Control + left mouse button to cut along the max stress region.
  4. Click Shift and scroll with the mouse to move the display toward the max location.


    Figure 5.
  5. For Structural 1, on the Analysis Workbench select (Pick info).
  6. In the dialog, select the Linearized stress tab.
  7. Under Stress linearization segment, activate the Custom radio button.
  8. In the modeling window, select two points on the model to draw a line segment.


    Figure 6.
    As with Method 1, the linearized stress calculation is performed and values are posted in the table in the Pick info dialog.


    Figure 7.

Save to CSV

Save the linearized stress values to a .csv file.

In the Pick info dialog, click Save to CSV.
The values for all line segments are written into a .csv file as shown in Figure 8.


Figure 8.

Optional: Edit Failure Criteria

Edit the failure criteria for linearized stress calculations.

  1. In the Pick info dialog under Failure criteria, set the Membrane stress to 100.


    Figure 9.

    Cells with Membrane stress above 100MPa are shown in red. The line segment status is changed to "Failed" and the segment is shown in red.

  2. Click Close.