Quality Feel (Static) Analysis

Tutorial Level: Intermediate In this tutorial, you will use SnRD to identify squeak and rattles for Static load.

In various industries, the perceived quality is measured by the touch and feel of the product. While being a subjective topic, the engineering community has broken down this assessment to different load cases. One of them is the Quality feel, which consists of applying a static force on different locations on the product, simulating a consumer touching or pressing the parts. The first assessment is to measure the stiffness [N/mm] and compare it to the target. While the stiffness can be acceptable, squeak issues can occur. These are the result of stick-slip between parts touching each other. With the SnRD Static loadcase setup and the associated post-processing capabilities, analysts can evaluate squeak and rattles under static loads.
The objectives of this tutorial are:
  • Prepare the FE model for analysis of squeak and rattle issues.
  • Apply a static load of amplitude -5.55 to the certain node(s) on Lower Control Panel component. This simulates a touch point scenario.
  • Run analysis and post-process the results.

For this tutorial, you can use a new model and prepare the model analysis setup. Alternatively, you can download the starting files below.

To prepare the model analysis setup yourself, refer to the following sections from the Detailed Risk and Root Cause Analysis tutorial for the workflow:Import a model with E-Lines. For this workflow, you can use the model with E-Lines created in the Detailed Risk and Root Cause Analysis usecase without the Dynamic Loadcase.

Choose the workflow according to your needs and refer to the sections mentioned above for the procedures. Once you have a model with E-Lines, you can proceed with the Static Loadcase Setup process.

Before you begin, copy the file(s) used in this tutorial to your working directory:

Import Model, DTS, and Material File

In this step, you will use the Import tool to import the required files.

  1. From the HyperMesh NVH menu bar, select Squeak and Rattle.
    The SnRPre and SnRPost ribbons open.
  2. From the SnRPre ribbon, select the Import tool.
    Figure 1.


    The Model Import dialog opens.
  3. Click , browse and select the tutorial_ip_snr_model.hm file.
  4. Click and specify the DTS File and Material File as tutorial_ip_snr_model_pre_output.csv and Tutorial_materialdb_snr.csv.
    Figure 2.


  5. Click Import.
    The selected model, DTS, and material file are imported to the session.
    Figure 3.

Define Static Loadcase

In this step, you will create a Static loadcase.

  1. From the SnRPre ribbon, select the arrow next to the Dynamic Event tool and select Static Event.
    Figure 4.
    The guide bar opens.
  2. On the guide bar, click and select One for all selected Nodes for Load Case Creation.
    Figure 5.


  3. In the modeling window, select the following nodes in the Lower Control Panel component.
    • 493552
    • 493543
    • 493563
    • 493478
    • 493477
    • 493518
    • 493503
    • 493494
    • 493530
    Figure 6.
  4. In the microdialog, select F.
  5. For the amplitude, enter -5.55.
  6. For the load direction, select X.
    Figure 7.
  7. Click .
    The Force loads at the selected nodes are created. The respective load collectors are created and listed in the Model Browser.

Define Constraint and Export Solver Deck

In this step, you will define model constraints.

  1. From the SnRPre ribbon, select the Constraints tool from the Static Event tool group.
    Figure 8.
    A guide bar opens.
  2. From the modeling window, select the node shown in Figure 9.
    Figure 9.
  3. In the microdialog, select SnRD_STATIC_FORCE_1_X for the Loadstep option.
  4. Select all degrees of freedom.
    Figure 10.
  5. Click .
    The Static loadcase with the load collectors and other entities required for the simulation is created. Respective load collectors get created and are assigned to the loadstep.
  6. From the SnRPre ribbon, select the Review Loadcases tool from the Run tool group.
    Figure 11.


    The Load Step Table dialog opens.
  7. In the Dynamic tab, deselect the dynamic loadstep.
  8. From the Static tab, select the static subcase.
    Figure 12.


  9. From the SnRPre ribbon, Analyze group, select the Export tool.
    Figure 13.
    The Model Export dialog opens.
    Figure 14.
  10. Click Export.
    A folder selection dialog opens.
  11. Browse and select the required folder.
    The OptiStruct solver deck is exported to the selected folder.
  12. Click Close to close the Model Export dialog.

Post Process Static Results

In this step, you will use SnRD Post to post process the results.

  1. From the SnRPost ribbon, select the Risk Assessment tool.
    Figure 15.


    The SnR Risk Assessment Browser opens.
  2. For Result File, select the tutorial_ip_snr_model.h3d file.
    A working status dialog opens while reading the H3D data. However, need to make sure the fem file is loaded in SNR Pre first.
  3. Under Subcase Selection, select the subcase.
    The rattle and squeak lines are segregated into separate tabs.
  4. Select the 60029 and 70009 line IDs which are required to perform post-processing.
  5. For SEP, enter 0.
  6. Verify Full Analysis is selected to see the line-level plots and to continue to next steps of post-processing.
    Important: You must perform full analysis to access Sensitivity Analysis and combined loading capabilities.
    Note: If Full Analysis is not selected, only a summary analysis is generated. Full Analysis is selected by default.
    Figure 16.


  7. Click Plot.
    Note: Execution of the Full Analysis will take a considerable amount of time to chart histograms and plot contours based on the machine's performance.
    An execution success message opens.
    Figure 17.
  8. Click Close.
Full analysis creates seven pages containing all the details. The summary for rattle analysis can be found on page one.
Figure 18. Rattle Summary Linear
Summary for squeak analysis can be found on page eight.
Figure 19. Squeak Summary Linear

From the results, you can observe that there are no squeak and rattle issues in the model for the applied static force. You can verify the issues by increasing the force amplitude and re-run the post processing.