7. C modeling#
7.1. Characteristics of modeling#
In this modeling, damping is added to the model (AMOR_ALPHA = 10-4, AMOR_BETA = 1). The modification procedure is started via the macro command CALC_ESSAI. Method LMME (Local Model Modeshapes Expansion) is used to calculate the expansion base.
7.2. Characteristics of the mesh#
« Support » model:
Number and type of mesh: 9 elements of type SEG2.
« Modification » template:
Number and type of mesh: 2 elements of type SEG2.
7.3. Features tested#
The structural modification procedure takes place in several steps. We test the smooth running of this procedure and the following functionalities:
LIRE_RESU, PROJ_MESU_MODAL, MACR_ELEM_STAT, ASSE_MAILLAGE, DEPL_INTERNE,, MAC_MODES, CALC_ESSAI.
7.4. Tested sizes and results#
The values of the first two natural frequencies of the modified structure are checked.
We also check the sum of the terms of the \(\mathrm{MAC}\) matrix (Modal Assurance Criterion) obtained between the deformations at the interfaces for the coupled model and the deformations at the interfaces by static expansion of the deformations of the coupled model obtained at the points of measurement. This indicator indicates the relevance of the reconstruction of the field at the interfaces. Criterion \(\mathrm{IERI}\) is also calculated for the first two modes of the structure.
Size tested |
Reference |
Aster |
Difference |
|
\(\mathrm{f1}\) |
|
7.7842 Hz |
0.044% |
|
\(\mathrm{f2}\) |
|
32.848 Hz |
0.009% |
|
\(\mathrm{MAC}\) (Sum) |
2 |
1.99994 |
|
|
\(\mathrm{IERI}\) stiffness \((\mathrm{1,1})\) |
0 |
4.60 10-7 |
4.60 10-7 |
4.60 10-7 |
\(\mathrm{IERI}\) mass \((\mathrm{2,2})\) |
0 |
3.17 10-12 |
3.17 10-12 |
3.17 10-12 |