3.9 Reference model

In DIRAC 2025R1 (4.4) you can import modal models from FE software packages. We refer to those as reference models. To import reference models, you need the dir-validate license.

Supported datasets

DIRAC only supports modal models in .uff formats. In addition, the reference models need to have the following requirements:

1. Dataset type 15: it defines the nodes and their coordinates.
2. Dataset type 18 (optional): if a non-global coordinate system is used.
3. Dataset type 55: it defines the mode shapers for each mode.

Importing reference models

To import reference models from List Mode, follow these steps:

1. Toggle on the List Mode.
2. Open the Item Overview card.
3. Go to the Reference Model tab.
4. Click the “+” button and browse for the model.

Visualizing the reference model

After importing the reference models, you can visualize them in the 3D Viewer. In addition, you can:

• Toggle the visibility
• Change the node color and size
• Display the heatmap
• Toggle the node mapping visibility (the line that connects the mapped node and the sensor)

All these options can be edited in the Item details card after selecting the Reference model in the 3D Viewer.

Visualizing the heatmap

In the 3D Viewer, you can visualize the mode shapes of the reference model with a heatmap. In this representation, node color indicates the magnitude of the selected mode shape.

To display the heatmap, complete the next steps:

1. Select the reference model in 3D Viewer.
2. Open the Item Details widget.
3. Select the checkmark on Heatmap.
4. Select the mode shape you want to display in Mode Selector column