DoE/Stochastics

Use DoE/Stochastics to understand the parameter variation study.

DoE and Stochastics module allows you to investigate hundreds of simulation results in a powerful way. When multiple variational studies have been setup, and results imported, SnRD will automatically post process all the Rattle and Squeak results for high level and deep dive investigation. You can refer to Variabilities Analysis for more information.
Use the exported TPL file in Altair HyperStudy to generate DoE/Stochastics results database and reports required for DoE/Stochastics study.
Tip: Learn more about Altair HyperStudy.

Evaluate DoE/Stochastics

Steps to evaluate DoE/Stochastics runs.

  1. Browse and select the OptiStruct (.FEM) solver file, pre output CSV and the results file using the Post Processing tab.
  2. Click DoE/Stochastics tab.
  3. Click HyperStudy Results Database.
  4. Click to browse and select XML file exported for Variability Study.
  5. Click Calculate.
    Once complete, a user message will appear.
  6. Click OK
  7. Click Apply Filters.
    This lists the runs for the selected filters.
  8. Click Display Results.
    This lists and displays the results for selected filters.
  9. Optional: Click SnR Results Database.
  10. Select the required options under Data Filtering panel.
  11. Select the required runs from the Run Selection list.
  12. Click Display Selection.
    The results for the selected runs are plotted.

Dynamic Event Options

Description of Dynamic loadcase options.

Below are the options available for dynamic loadcase setup.

Load Curve

Load Curve
Sine Sweep
Sinusoidal or Sine sweep is a sine function that gradually changes frequency over time.
Only Displacement load type is supported.
From File
Use this option to import a file containing the load time history. SnRD supports loading either one, two, or three directions.

Refer From File Options.

Note: When more than one load direction is created at the same time, SnRD will automatically create one Loadcase for each direction and one with all directions combined. Example: Applying a load on one node in three directions at the same time will create four loadcases.
Figure 1.
From PSD
PSD: Power Spectral Density

An Input PSD curve (Acceleration vs Freq) is converted into a signal in timedomain depending on the selection of loadtype and Time length.

From Curve
Use already existing curves (TABLED1) in session as load curves. You will be prompted to select which curve is used for which direction.
Undo Dynamic Event ()
Reverts the recently created dynamic event.
You can revert the creation only if Curve Editor () is chosen.
Curve Editor ()
Launches the Curve Editor after creation of loadcase which allows for preview of the imported load curve(s).
Modes
Defines data for Eigenvalue analysis (EIGRL/EIGRA)
Method
Select Eigenvalue method, Lancos or Amses.
Defines data required to perform real eigenvalue analysis (vibration or buckling) with the Lanczos Method.
Frequency Range
Define which frequency range to consider in evaluation.
No of Modes to Extract

Set the number of modes to extract. If set to blank all modes in Frequency range are extracted.

Damping
Defines damping parameters (TABDMP1)
Damping
Define damping factor as constant over all frequencies or through a table.
Method
Set damping method.
Time Step
Defines Time Step Parameters (TSTEP)
Auto Time Step
Automatically extracts Time Step based on load curve.
Auto No of Time Steps
Automatically extracts number of time steps based on load curve.
Output frequency
Defines the output frequency of the results at the respective time steps.
Output
Displacement
Output displacement on all E-Lines.
Velocity
Output Velocity on all E-Lines.
GPForce
Grid point force on all E-Lines.

The Supported format for loadcurve data is CSV and TXT and columns in file should be organized depending on your selection as shown below:

Note: Supported format for loadcurve data is CSV and TXT and columns in file should be organized depending on your selection as shown below:
One direction-
TIME, DIR1
One direction sample file is shown below-
Figure 2.
Three Directions-
TIME, X, Y, Z
Three directions sample file is shown below-
Figure 3.
Two Directions XY-
TIME, X, Y
X,Y direction loading sample file is shown below-
Figure 4.
Two Directions XZ-
TIME, X, Z
X,Z direction loading sample file is shown below-
Figure 5.