8.3 Visualizing results

Mode shapes

You can visualize the mode shapes in the 3D Viewer.

To visualize the mode shapes, complete the next steps:

1. Select the mode from Modes card.
2. Toggle the Mode shape button.

FRFs and modal residuals

In the Graphing card, you can visualize all the different curves:

• Original FRF: the original preset.
• Fitted FRF: FRF rebuilt from your modal residues.
• Synthesized FRF: FRF rebuilt from the globalized mode shapes.
• Residue mode: FRF rebuilt from the modal residue of only the selected mode (and any lower residual).
• Normal mode: FRF rebuilt from the globalized mode shape of only the selected mode (and any lower residual).

To visualize the desired curve, complete the next steps:

1. Right-click on the accelerance graph.
2. Select Display Curves.
3. Select the desired curve.
4. For normal and residue modes, select the desired mode in the Modes card.

MAC and similarity

The MAC (Modal Assurance Criterion) matrix allows you to verify how similar the mode shapes are to one another. In DIRAC, the MAC is only applied to the test-data, and not the numerical ones. The similarity matrix shows the average similarity of the reconstructed FRFs to the measured ones.

To visualize the MAC or similarity matrix, you have to:

1. Click on the MAC or Similarity button in the Matrix card.

Nyquist diagram

In the Nyquist diagram, you can visualize the original FRF and the FRFs resulting from the latest Modal Analysis computed.

To visualize the Nyquist diagram, complete the next steps:

1. Select the desired inputs.
2. Slide the slider over the desired frequency range in the frequency plot below the Nyquist.