Calculating in-situ Blocked Forces

On this page, you will learn all the necessary steps to calculate Blocked Forces using the in-situ method in SOURCE, to make an on-board validation. At the end, you will find some additional steps that VIBES recommends to perform to check the quality of your data.

Essential steps

Import FRF data

To do an analysis in SOURCE, the first step consists of importing the FRF data. We recommend directly importing a DIRAC project because it gives the most efficient workflow and unlocks additional functionalities.

To import and load FRFs from a DIRAC project, complete the next steps:

1. Drag and drop the DIRAC project into the FRF Data card. The import dialog will appear.
2. Select the correct FRF from the FRF matrices‘ list.
3. Press OK.

Import operational data

To analyze your operational data, you need to import them into SOURCE. SOURCE supports ATFX and MAT files. You can do a bulk import of multiple files at once, by importing the folder that contains them all.

To import operational data, complete the next steps:

1. Drag and drop the operational data into the Operational Data card.

or

1. Click on the + button in the Operational Data card.
2. Browse for the data.

Set up channels

To do an analysis, you need to set up your channels. In particular, you have to:

• Define the Master Channels.
• Map the channels to the Masters.
• Set the correct channel type.

In SOURCE, all these steps can be done during the import phase. In some cases, e.g. if the operational and FRF channels have different names, you need to do these actions manually.

Define the Master channels

Before jumping to the analysis, you need to set which channels SOURCE will use for the calculation, and set them as Masters. We recommend to set the FRF data channels as Masters, to be sure to also include the Virtual Point forces and moments. To set the channels as Masters, you have to:

1. Go to the FRF Data module (or Operational Data).
2. Click on the Channel Mapping icon.
3. Select on the left the channels that should be set as Masters.
4. Drag and drop them in the Master channels column.

Map channels to the masters

After setting the FRF channels as Masters, you need to map the operational data channels to the corresponding ones.

If FRF and operational data channels have the same name, the mapping can be done automatically during the import. If this is not done, you can map channels following the next steps:

1. Go to the Operational Data module.
2. Right-click on the operational dataset to map.
3. Select Copy Channel Mapping From.
4. Select Master Channels.

If FRF and operational data channels have different names, you have to perform the mapping manually. To manually map channels, follow the next steps:

1. Go to the Operational Data module.
2. Click on the Channels icon.
3. In the Operational Data card, select the dataset to map.
4. Select one or multiple channels from the left column.
5. Drag and drop them to the corresponding channels on the right side.

Set the correct channel type

The next step consists of setting the correct channel type. For this type of analysis, you need to set the following types:

• Virtual Point channels: set as Forces.
• Channels to use for the characterization: set as Indicator Responses.
• Channels to use for the syntheses: set as Validations.

To change the channel type, complete the next steps:

1. Click on the Channels icon.
2. In the Master channels column (on the right side), select the channel(s) to be edited.
3. Right-click on it/them.
4. Select Set Channel Type.
5. Select the correct type.

Calculate Blocked Forces

After importing the data and setting the channels, you can proceed to make the analysis and calculate Blocked Forces.

To calculate Blocked Forces, complete the next steps:

1. Go to the Analyze module.
2. Click the + button at the top left. A menu will appear.
3. Select In-situ. A new analysis is created.
4. Select the analysis.
5. Click on Operational Data in the Inputs card and select the operational data you want to analyze.
6. Click on FRF Data in the Inputs card and select the FRF data you want to use in the analysis.
7. Go to Settings and edit them according to your preferences, if needed.
8. Click on the calculator symbol next to your analysis, to run it.

Make an on-board validation

After calculating Blocked Forces, you can make an on-board validation. The TPA syntheses are automatically calculated in the analysis, so you just need to plot them.

To visualize the on-board validation, complete the next steps:

1. Go to the Results card.
2. Select the operational data and the Component TPA synthesis.
3. Drag and drop them in the graphing space.

VIBES recommendation

Create sequences

If you are not interested in the full dataset, but just in some portions, it is possible to extract the data of interest by cropping segments and merging them into sequences. This is only possible for Time Series.

To create segments and sequences, follow the instructions at this link.

Check CMIF

To check your FRF data, you can plot them in the Graph card and visualize their overall magnitude and coherence in the Matrix Viewer. You can plot single FRFs or visualize the singular value breakdown, often referred to as Complex Mode Indicator Function (CMIF).

To plot FRF or CMIF, follow the instructions at this link.

Check ODS

Check operational consistency

Operational consistency can be used to reveal incorrect behavior in the operational measurements, such as overloads, non-linear phenomena, moved or loose sensors and inconsistent sensor movement. It works by evaluating the consistency of the response data through the Virtual Point Transformation. To plot the operational consistency, follow the instructions at this link.