Basic Screening Risk Analysis

Use SnRD to identify Squeak and Rattle issues.

This tutorial describes the basic screening analysis that the S&R analyst would perform. Starting from a NVH FE-model, the analyst wants to define a first set of Evaluation-lines (E-Lines) to assess the S&R performance of a system. Typically, this first analysis will occur at the early stage of the virtual development process, thus a lack of input might be a road blocker for the S&R CAE engineer. Therefore, the SnRD simple process will close this gap by offering automation and a set of default settings enabling this first analysis.

Typical information lacking at this stage of the development are:
  • Interface to be analyzed
  • Detailed Gap, dimensioning and tolerance data
  • Loading Conditions

The objective of this tutorial is to create E-Lines to evaluate Squeak and Rattle, define a SineSweep loadcase, and evaluate risks.

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

Import Model

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

  1. Using the file browser option in the Model Import field, browse and select the file.
  2. Click Import.
    The selected model is imported to the session.
    Figure 1.

Create Geometric Lines

In this step, you will define the interface between components by using the Create Geometric Lines tool to create geometric lines in the model.

  1. In the HyperWorks toolbar, click option, and select QuickReviewComps.
    Figure 2.
    The components you want to include in the evaluation are isolated.
  2. From Setup group, select Define Interface.
    Figure 3.
    A guide bar opens.
  3. From the guide bar, click to open advanced options.
    Figure 4.
  4. Enable the Min checkbox and enter 800 as the input value.
  5. Select the complete model from graphics area.
  6. Click .
    The geometric lines are created at the component edges in the model. Twelve lines should be created.

Create E-Lines

In this step, you will create and manage all the E-Lines in the model.

Use Create E-Lines tool to create E-Lines at the interfaces.
  1. From Setup group, select Create E-Line tool.
    Figure 5.
    A guide bar opens.
  2. From the guide bar, verify components is active and select all the components in the model.
  3. From the guide bar, select Lines and select all the lines in the model.
  4. Enable the Realize checkbox.
  5. Click .
    Eleven E-Lines are created in the model.
    Figure 6.

Manage E-Lines

In this step, you will use the Manage E-Lines tool to review E-Lines in the model.

  1. From Setup group, select Manage E-Lines > Review E-Lines.
    Figure 7.
    The Review E-Line dialog opens containing a table.
    Figure 8.
  2. Use the arrows to review each E-Line.
  3. Optional: Name all E-Lines.

SineSweep Loadcase Setup

  1. From Setup group, select Dynamic Event.
    Figure 9.
    A guide bar opens.
  2. From the guide bar, click to view advanced options.
  3. For Output Frequency under Time Step, enter 4.
    Figure 10.
  4. In the graphics area, select the node shown in Figure 11.
    Figure 11.
    A microdialog opens.
    Figure 12.
  5. For displacement, select D.
  6. For Load Curve, select Sine Sweep.
  7. For load direction, select Z.
  8. Click .
    The SineSweep loadcase is created. The Curve Editor dialog opens.
  9. Review the SineSweep load curve and close the Curve Editor dialog.
  10. Setup Constraints for the other Degree of freedoms (DOFs) on the same node using:

    Figure 13.
  11. Select the node.
  12. In the microdialog, select the loadcase which was just created (SnRD_Dyn_Disp_#_Z) and Lock all DOFs beside Z translational.

    Figure 14.
  13. Click .
The Boundary Constraints are created and assigned to the loadcase.

Export OptiStruct Solver File

  1. From Analyze group, select Export OptiStruct Solver File.
    Figure 15.
    The Model Export dialog opens.
    Figure 16.
  2. Click Export.
    A folder selection dialog opens.
  3. Browse and select the required folder.
    The OptiStruct solver deck file is exported to the selected folder.
Use the exported .FEM solver deck to solve with OptiStruct solver. Once completed, two result files are generated: .H3D and .PCH. These files will be used in the Post Processing of results.

Risk Assessment

In this step, you will evaluate risks for Squeak and Rattle in the Risk Assessment.

  1. Open Risk Assessment.
    Figure 17.
  2. Select the .pch file generated after solving the model file.
    The Sinesweep loadcase is selected in the Load Step list.
  3. In the Rattle Tab, select Relative Displacement MAG.
  4. Click Plot.
    The Relative Displacement for the E-Lines are visualized.
    Figure 18.
  5. Optional: Review the summary of all E-Lines in the model for the active loadcase and result file by clicking .
    Tip: If loading results are from additional result files and loadcases, then these results will be appended to the Summary Table which allows you to conduct easy comparisons of design iterations.

Generate Summary Report

In this step, you will export a Squeak and Rattle summary report using the Report tool.

  1. From the Analyze group, select the Report tool.
    The Risk Assessment Report dialog opens.
  2. Enter a name for the report and select which results to include.
    Figure 19.
  3. Click Export and select location to save the report.
  4. Review the report.

    Figure 20.