Perform Sensitivity Analysis

Use a sensitivity analysis to study modal contribution.

The standard post-processing in SnRD can be used to generate time domain displacement plots of each of the node-pairs of all the E-Lines that are present in the model. The purpose of the sensitivity analysis is to study the root cause of rattle and/or squeak at each E-Line.

Two main diagnosis functionalities are enabled in SnRD sensitivity analysis step:
  • Determination of Relative Modal Contribution to squeak and rattle of complete E-Lines and as well as at specific points on each E-Line.
  • Capability to check the effect of changing the percentage of modal contribution on the squeak and rattle performance.
Sensitivity analysis is a two step process:
  1. Calculate the relative Modal Contribution of the required E-Line to be analyzed.
  2. Observe the change in results.

    Specifically, when the modal contribution is varied by either including or excluding a certain mode from the result calculations with a modal sensitivity study.

    The relative modal contribution for a particular E-Line can be calculated and studied in two ways:
    • Study the modal contribution of the complete E-Line.
    • Study the modal contribution of a particular node pair of an E-Line.
  1. From the SnRPost ribbon, select the Sensitivity Analysis tool.
    Figure 1.


    The SnR Sensitivity Analysis Browser opens.
  2. Select the required result file.
  3. Select the subcase.
  4. For Modal Results File (.h3d), browse and select the relevant H3D file.
  5. Select the required E-Line.
  6. Select a point on the E-Line or select a check box.
  7. Select a direction.
  8. Optional: Select the Display Excitation load check box to plot the excitation load.
  9. Optional: Select the Squeak 2D Plot check box to plot the relative displacement in the XY plane (Contact Plane).
  10. Click Load Time History.
    Loading time history and relative displacement plots for the selected E-Line and the pair are generated and plotted.