4. B modeling#
4.1. Characteristics of modeling#
Model A is repeated, but by adding damping to the mass/spring system.
Discreet element in type translation DIS_T
Characteristics of the elements:
At nodes \(\mathrm{P1}\) and \(\mathrm{P2}\): mass matrices of type M_T_D_N with \(m=100\mathrm{kg}\).
Between \(\mathrm{P1}\) and \(\mathrm{P2}\): a K_T_D_L stiffness matrix with \({K}_{x}={10}^{6}N/m\)
Boundary conditions:
All degrees of freedom are locked except degree of freedom \(\mathrm{DX}\) from node \(\mathrm{P2}\).
Damping: A \(\mathrm{0,1}\text{}\) reduction in damping is added to the system.
It is introduced into the test case, either usually by the keyword AMOR_REDUIT, or, to validate the functionality RELA_EFFO_VITE, by a linear relationship between the mass/spring speed and a force applied to the node \(\mathrm{P2}\).
4.2. Characteristics of the mesh#
Number of knots: 2
Number of meshes and types: 1 SEG2, 2 POI1
4.3. Features tested#
In particular, in this modeling, the functionality RELA_EFFO_VITE of the DYNA_VIBRA operator (BASE_CALCUL =” GENE “) is tested in this modeling. Through its use, it is possible to introduce a non-linear behavior dependent on the speed of a point. Here we validate this relationship in a simple way in the linear case by comparing it with a modal damping behavior (which, in the case of a single mode, amounts to viscous damping).
4.4. Tested sizes and results#
Identification |
Reference |
Tolerance |
DYNA_VIBRA (BASE_CALCUL =” GENE “) AMOR_REDUIT |
|
1% |
DYNA_VIBRA (BASE_CALCUL =” GENE “) RELA_EFFO_VITE |
|
1% |
DYNA_VIBRA (BASE_CALCUL =” GENE “) AMOR_REDUIT |
|
1.E -4% |
DYNA_VIBRA (BASE_CALCUL =” GENE “) RELA_EFFO_VITE |
|
1.E -4% |