Quality Feel (Static) Analysis

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, use a new model and prepare the model analysis setup. For this workflow, refer to the following sections from the Detailed Risk and Root Cause Analysis tutorial: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:

Define Static Loadcase

In this step, you will create a Static loadcase.

  1. From the HyperMesh NVH menu bar, select Squeak and Rattle.
    The SnRPre and SnRPost ribbons open.
  2. From the SnRPre ribbon, select the arrow next to the Dynamic Event tool and select Static Event.
    Figure 1.
  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 2.
  4. In the microdialog, select F.
  5. For the amplitude, enter -5.55.
  6. For the load direction, select X.
    Figure 3.
  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

In this step, you will define model constraints.

  1. From the SnRPre ribbon, select the Constraints tool from the Static Event tool group.
    Figure 4.
    A guide bar opens.
  2. From the modeling window, select the node shown in Figure 5.
    Figure 5.
  3. In the microdialog, select SnRD_STATIC_FORCE_1_X for the Loadstep option.
  4. Select all degrees of freedom.
    Figure 6.
  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.

Import model and Results File

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

  1. Open HyperView.
  2. From the menu bar, click File > Load > Preferences File.
    The Preferences dialog opens.
  3. In the Preferences dialog, select Squeak & Rattle and click Load.
    The SnRD menu is created in the HyperView client.
  4. Select SnRD > SnRD-Post.
    The SnRD Post Processing tool opens.
    Figure 7.
  5. Using the file browse option , select the OptiStruct solver file which was exported in Export OptiStruct Solver File for Model File.
    Note: Pre output CSV file containing the E-Lines definition is sourced automatically.
  6. Click .
    A file browser window will appear.
  7. Select the tutorial_ip_snr_model.h3d file from tutorials folder.
    A working status dialog opens while reading the H3D data.
  8. Enable the checkbox against the subcase in the Subcase selection table.
  9. Click in the Save Session File entry field.
  10. Browse and select the required folder where the post processing session and data will be stored.
    Figure 8.

Post Processing

In this step, you will perform Full Analysis to understand the squeak and rattle risks in the model.

  1. In the Post Processing tab, define the following parameters.
    1. For Analysis Type, select Rattle & Squeak.
    2. For Line(s) to Evaluation, select All.
    3. For % statistical evaluation, enter 0.
    4. For Session Type, select Full Analysis.
  2. Click Execute.
    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 9.
  3. Click Close.
Full analysis creates 11 pages containing all the details. The summary for rattle analysis can be found on page one.
Figure 10. Rattle Summary Linear
Summary for squeak analysis can be found on page eight.
Figure 11. 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.