COMPUTER-ANWENDUNGENUND INFORMATIONS-
TECHNOLOGIE
Graphical simulation of stress ratios on the surface of a rotor hub |
||
|
The task:
The task was the finite element calculation of a rotor hub as used in wind power plants. On the basis of these calculations, the stress ratio on the rotor hub was to be calculated and graphed under various conditions, such as storm or when rotor is in rotation or stationary. The solution: Due to the complicated three-dimensional geometry of the hub, a model was made with volume elements. Ancillary conditions and force effects were modelled with bar and beam elements. As a volume model involves too many degrees of freedom, a full model was not calculated but a half-model on the basis of symmetry characteristics. The hub wall was elemented with volume elements (three-dimensional, thick shells, isoparametric elements with quadratic trial functions). To determine the stress on the surface, the hub surface was covered with thin shell elements consistent with the volume elements. The thickness of these shell elements was made negligibly small so that the influence on the elastic model does not have to be taken into account. Force effects were simulated with "screens" made of beams. The actual load ratios were ascertained with linear combinations of standard cases of the symmetric and antisymmetric half-model. |
click the pictures for enlargement | |
|
|
|
|
|
|
|
|
|
Phone: 040 / 51 437 - 0
Fax: 040 / 51 437 - 130
e-mail: Vertrieb@caitec.de