The mode shapes do not represent "deformations" with result values in [mm] or [mrad], as is the case with a static analysis. Rather, the displacements and rotations are scaled to the maximum value of 1. Therefore, they are referred to as 'Normalized Displacements' and 'Normalized Rotations' in the table headings.
In the category Scaling the mode shapes at the bottom of the ' Navigator - Results ', you can choose from various options with which you can 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 vector uj to 1.
With this scaling, only the translation components are considered.
| uj | Translational component (j is the direction X/Y/Z) |
max {uX ; uY ; uZ } = 1
With the second option, the maximum translation component of the eigenmode vector is sought and this is set to 1.
| uj | Translational component (j is the direction X/Y/Z) |
If you check the results in the graphic, you should activate one of the displacement components. With the eigenform of the vector | u | values greater than 1 are possible.
max {uX ; uY ; uZ ; φX ; φY ; φZ } = 1
This approach takes into account the entire eigenvector including the rotational components. The maximum is sought as a reference and this portion is then set to 1.
| uj | Translational component (j ... direction X/Y/Z) |
| 𝜑j | Rotational component (j ... direction X/Y/Z) |
From the mass matrix {uj }T [M] {uj } = 1
With the last option, the modal masses mi are set to 1 kg for each eigenvalue.
This approach is always used internally in the calculation for the time history or response spectrum method, even if a different setting is specified in the Navigator. In the table # extbookmark manual|TABLE_EFFECTIVE_MODAL_MASSES|Effective modal masses # change in the first column all modal masses Mi to 1 kg.