Spot Weld (CBAR)

In this tutorial you will:

Import a model to HyperLife
Select the Weld module and define its required parameters
Create and assign materials to the welds and sheet groups
Assign load histories for scaling the stresses from FEA subcases
Evaluate and view results

Prior to running through this tutorial, copy Models-h3d.zip from <HyperWorks_installation_directory>\tutorials\hl to a local directory. Extract Rail_SpotWeld.h3d and Rail_SpotWeld.force from Models-h3d.zip..

Import the Model

ELFORCES are required for this analysis.

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

Figure 1.
From the Load model and result dialog, browse and select Rail_SpotWeld.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.
Note: The .h3d file should contain the following result types for this calculation:
- CBAR/CBEAM Axial Force A
- CBAR/CBEAM Shear Plane - 1A
- CBAR/CBEAM Shear Plane - 2A
- CBAR/CBEAM Torque A
- CBAR/CBEAM Bending Plane - 1A
- CBAR/CBEAM Bending Plane - 2A
- CBAR/CBEAM Bending Plane - 1B
- CBAR/CBEAM Bending Plane - 2B
Click Apply.

Figure 2.

The spot welds are modelled with CBAR elements between the two plates.

Figure 3.

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

From the Setup tools, click the arrow next to the fatigue module icon and select the Weld tool from the list of options.

Figure 4.

The Weld dialog opens.
Accept the default parameters.

Figure 5.
Exit the dialog.

Assign Materials

From the Setup tools, click the Material tool.

Figure 6.

The Assign Material dialog opens.
Activate the checkboxes for the Grp_1 and Grp_2 sheet groups.
Click the My Material tab.
Click .
A new material named Mat_WELD("n") is created.
Select Estimate from UTS as the input method.
Select Steel as the type and enter a value of 1200 for UTS.
Click Estimate to obtain SN parameters.
Enter a value of 1.0 for the standard error.

Figure 7.
Click Plot & Save.
Right-click on Mat_Weld("n") and select Add to Assign Material List.
Return to the Assign Material Data tab.
Select Mat_Weld("n") from the Material drop-down menu for every part.
For both groups, enter a value of 2.0 for the Thickness/Diameter of Sheet 2.
For both groups, enter a value of 8.0 for the Thickness/Diameter of Nugget.

Figure 8.
Exit the dialog.

Assign Load Histories

From the Setup tools, click the Load Map tool.

Figure 9.

The Load Map dialog opens.
From the Load Type menu, select Constant Amplitude.
Click to add the load case.

Tip: Click to view a plot of the load.

Figure 10.
On the bottom half of the dialog, set the radio button to Auto for event creation and select Single Event from the drop-down menu.
This option assists in automatically creating an event based on the subcase and channel selection.
Select both Subcase 1 and ConsAmpEvent1 and click next to Single Event.
An Event_1 header is created.
Select Subcase 2 and ConsAmpEvent1 and click .
An Event_2 header is created.
In a similar manner, create an Event_3 header.
Activate the check boxes for all three events.
Set LDM to 1.0, Scale to 8.0 and Offset to 0.0 for Subcase 1.
Right click on the Scale field for Subcase 1 and select Apply value to all events.

Figure 11.
Exit the dialog.

Evaluate and View Results

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

Figure 12.

The Evaluate dialog opens.

Figure 13.
Optional: Enter a name for the run.
Click Run.
Result files are saved to the home directory and the Run History dialog opens.

Figure 14.
Once the run is complete, click View Current Results.
Use the Results Explorer to visualize various types of results.

Figure 15.

Figure 16.

The life of the critical spot weld is around 6.212e09 cycles.