Rotating structures have conventionally been modeled by the lumped mass approach. This approach uses the center of mass to calculate the effects of rotation on attached or proximal components . A major limitation of this approach is the imprecise approximation of both the location and the distribution of the mass and inertias, along with the resulting inaccuracy in the calculation of internal forces and stresses in the components themselves.
The finite element (FE) method used in MAPDL offers an attractive approach to modeling a rotordynamic system. While it may require more computational resources compared to standard analyses, it has the following advantages:
Accurate modeling of the mass and inertia
A wide range of elements supporting gyroscopic effects
The use of the CAD geometry when meshing in solid elements
The ability of solid element meshes to account for the flexibility of the disk as well as the possible coupling between disk and shaft vibrations.
The ability to include stationary parts within the full model or as substructures.