Tested with CGX 2.19 / CCX 2.19 / Gmsh 4.9.3
- Use of distributing coupling to model bearings of a shaft (doesn not work any more in 2.19, needs to be converted to meanrot MPC)
- cad2fbd not tested in 2.19
- Modal analysis
| File | Contents |
|---|---|
| Welle.stp | Geometry, STEP format, generated using Autodesk INVENTOR |
| Welle.geo | Gmsh script for geometry and mesh |
| run.fbl | CGX script, meshing with CGX |
| gmsh.fbl | CGX script, meshing with Gmsh |
| test.py | Python script to run the full simulation |
The geometry represents a gearbox shaft with bearing journals at the ends. These are modeled using distributing coupling of the cylindrical bearing surfaces. The translations of their centroid is controlled by the displacement of the reference nodes.
Note that this works only for solid elements (not for shells).
> cgx -b run.fbl
Constraints of the ref nodes
- red: ux,uy,uz = 0
- blue: uy, uz = 0
The shaft is free to rotate.
Bending modes rotate about the centers of the bearing surfaces
(2.19: no support at all due to distributing coupling being a pure load distribution, not a dof coupling) The left bearing is constrained in longitudinal direction (x), the right one is not. It is clearly visible that the bearing surfaces can deform (which they could not with kinematic coupling)
In CGX 2.12 there was a bug, which resulted in fail of meshing the geometry. Therefore, an alternative simulation with gmsh as pre-processor has been set up.
> cgx -b gmsh.fbl
