The mode shapes do not represent "deformations" with result values in [mm] or [mrad], as is the case of a structural analysis. The displacements and rotations are rather scaled to the maximum value of 1. Therefore, they are referred to as "Normalized Displacements" and "Normalized Rotations" in the table headings.
The Scaling of Mode Shapes category at the bottom of the "Navigator – Results" provides various options that you can use to influence the display of the mode shapes in the work window and in the tables.
|u| = 1
The first option scales the value of the mode shape vector uj to 1.
Using this scaling, only the translational components are taken into account.
| uj | Translational component (j is the direction X/Y/Z) |
max {uX; uY; uZ} = 1
The second option searches for the maximum translational component of the mode shape vector and this is set to 1.
| uj | Translational component (j is the direction X/Y/Z) |
When checking the results in the graphic, you should activate one of the displacement components. For the mode shape of the vector |u|, it is possible to apply values greater than 1.
max {uX; uY; uZ; φX; φY; φZ} = 1
This approach takes into account the entire eigenvector including rotational components. The maximum is sought as a reference and this component is then set to 1.
| uj | Translational component (j ... direction X/Y/Z) |
| 𝜑j | Rotational component (j ... direction X/Y/Z) |
From mass matrix {uj}T[M]{uj} = 1
With the last option, the modal masses mi are set to 1 kg for each mode shape.
This approach is always used internally in the time history or response spectrum analysis calculations, even though a different setting is specified in the Navigator. In the Effective Modal Masses table, all modal masses Mi change to 1 kg in the first column.