Order Analysis - Load

Perform file and result selection.

From the NVH-Utilities tab > Order Analysis > Load sub-tab, select an OptiStruct or Nastran result file to load. Once the file is read, subcases from the result file are matched to RPMs, or orders. The NVH utility attempts to automatically match the subcases and orders by using text information in the subcase label. If this fails, you must complete the Subcase identification section, located on the Subcase tab. Once the match is complete, click the Apply button to populate the Result selection fields, located on the Order Response tab.

File selection
From the Load tab > RPM/Order results field, select a frequency response file containing RPM-based loading subcases or order-based loading subcases and click Load. Once the file is read, subcases from the result file are matched to RPMs, or orders, and can be reviewed in the Subcase identification section, located on the Subcase tab. The NVH-Utility attempts to automatically match the subcases and orders by using text information in the subcase label. If this fails, you must complete the Subcase identification section and click Apply. Once the match is complete, the Order Response tab is displayed and the Result selection fields are populated.
Result selection
The following fields are available on the Order Response tab, under Result selection.
Result type
This field is populated based on available result types from the file loaded. Select a result type for order analysis.
Response ID
Grid ID of the response for which order analysis results are available. Select one from the list.
Response label (optional)
Enter a label that describes the response, for example, "Left Engine Mount".
Direction component (optional)
X, Y, Z, RX, RY, RZ, or XYZ Vector Sum.
Complex component
Magnitude or phase.
Range selection
Customize the RPM range and Frequency range fields as necessary.
Once your selections are complete, you can load the RPM-based response curves to generate a 3D surface plot.
Display Options
The Display Options dialog allows you to customize the surface plot, including scale, weighting, and the plot layout.
Plot Surface
Click to generate a 3D surface plot.
Order Cuts
After viewing the surface plot, use the Start, End, and Step fields to specify the orders you want to see by cutting the surface plot.
Combine Order By - Choose between RSS and Arithmetic Sum to determine how to combine the order curves to construct the overall response.
Display Options
The Display Options dialog allows you to customize the overall response plot, including scale, weighting, and the plot layout.
Load Response
Once your selections are complete, click Load Response to create the orders and order sum response overlay plot.
Figure 1. 3D Surface Plot (Waterfall Diagram)


Figure 2. 2D Line (Order Contribution Analysis)