HL-T: 1020 Multiaxial Stress-Life (S-N)

In this tutorial you will:
  • Import a model to HyperLife
  • Select the SN module and define its required parameters
  • Create and assign a material
  • Assign load histories for scaling the stresses from FEA subcases
  • Evaluate and view results
Before you begin, copy the file(s) used in this tutorial to your working directory.

Import the Model

  1. From the Home tools, Files tool group, click the Open Model tool.


    Figure 1.
  2. From the Load model and result dialog, browse and select HL-1020\Ibeam.h3d for the model file.
    The Load Result field is automatically populated. For this tutorial, the same file is used for both the model and the result.
  3. Click Apply.


    Figure 2.
Tip: Quickly import the model by dragging and dropping the .h3d file from a windows browser into the HyperLife modeling window.

Define the Fatigue Module

  1. Click the SN tool.
    The SN tool should be the default fatigue module selected. If it is not, click the arrow next to the fatigue module icon to display a list of available options.


    Figure 3.
    The SN dialog opens.
  2. Define the SN configuration parameters.
    1. Select Multi Axial as the method.
    2. Select MPa for the FE model units.
    3. Enter a value of 20 for the number of planes.
    4. Enter a value of 0.5 for the certainty of survival.
    5. Select GOODMAN for the Tension Damage Model.
    6. Select NONE for the Shear Damage Model.
    7. Select Worst for the layer selection.
    8. Select Time Series for the type of loading.


    Figure 4.
  3. Exit the dialog.

Assign Materials

  1. Click the Material tool.


    Figure 5.
    The Assign Material dialog opens.
  2. Activate the checkboxes next to the parts Flange and Web.
  3. Create a new material.
    1. Click the My Material tab.
    2. Click to create a new material.
    3. Name the material Mat_SN_multiaxial.
    4. Set the Elastic modulus to 200000.
    5. Set the Input method to Slope-intcept,2-seg.
    6. Accept all other default settings then click Plot & Save.


      Figure 6.
  4. Right-click on Mat_SN_multiaxial and select Add to Assign Material List.
  5. Return to the Assign Material Data tab and select Mat_SN_multiaxial from the Material drop-down menu for both Flange and Web.
    The Material list is populated with the materials selected from Material Database and My Material.


    Figure 7.
  6. Exit the dialog.

Assign Load Histories

  1. Click the Load Map tool.


    Figure 8.
    The Load Map dialog opens.
  2. From the Channel Type drop-down menu at the top of the dialog, select Time Data.
  3. Click in the Choose File field and browse for load1.csv.
  4. Click to add the load case.
  5. Repeat steps 3 and 4 for load2.csv, load3.csv, and load4.csv.
  6. Optional: Click to view a plot of the loads.


    Figure 9. Load 1


    Figure 10. Load 2


    Figure 11. Load 3


    Figure 12. Load 4
    Tip: Expand the width of the dialog to view a clearer picture of the plot.
  7. On the bottom half of the dialog, set the radio button to Auto for event creation.
  8. Select both the load 1 (block1) and load 2 (block1) channels and Subcase 1 and Subcase 2, then click to create the first event.
  9. In a similar manner, create a second event by selecting load 3 (block1), and load 4 (block1), Subcase 1, and Subcase 2.
  10. Activate the checkboxes for the two events.
  11. Set the Scale as shown in the image below.


    Figure 13.
  12. Exit the dialog.

Evaluate and View Results

  1. From the Evaluate tool group, click the Run Analysis tool.


    Figure 14.
    The Evaluate dialog opens.


    Figure 15.
  2. Optional: Enter a name for the run.
  3. Click Run.
    Result files are saved to the home directory and the Run Status dialog opens.
  4. Once the run is complete, click View Current Results.
  5. Use the Results Explorer to visualize various types of results.
    The contour below highlights the total damage (Event 1 + Event 2).


    Figure 16.


    Figure 17. Event 1: Damage matrix for element 18802


    Figure 18. Event 2: Damage matrix for element 18802