Tested with CGX 2.19 / CCX 2.19
- Test of how to couple structures to beam nodes in an average sense
- Reference nodes with and without knots
Observations:
- None of the methods can couple the rotations of a beam node (knot or not a knot) to a surface.
- Kinematic coupling pin-joines the reference node to the surface.
| File | Contents |
|---|---|
| test.fbl | Top level CGX script, full test program |
| run.fbl | CGX script, subprogram for a single simulation |
| modal.inp | CCX input |
| test.py | Python script to run the full simulation |
| Name | Coupling | Ref node | dofs |
|---|---|---|---|
| c_kin_load_123 | kinematic | normal | 1-3 |
| c_kin_center_123 | kinematic | knot | 1-3 |
The model consists of a beam and a disk with hole. The beam is fixed at x=0 (all dofs). The adjacent face of the disk is coupled either to the "center" node (which has a knot due to inverse beam normals at both sides) or to the "load" node at the free end (which is an ordinary node).
| Parameter | Value | Description |
|---|---|---|
| le | 100 | Length in mm |
| ri | 10 | Inner radius in mm |
| ra | 20 | Outer radius in mm |
| td | 5 | Thickness of the ring in mm |
| dist | 10 | Offset of the ring from the beam end in mm |
| num | 10 | Number of mode shape movies to generate |
A frequency analysis is performed to see how the coupling works.
> cgx -b test.fbl
Kinematic coupling to the end node. The disk is pin-joined to the ref node and can spin freely about that point. This is because the end node doesn't have a knot.
Kinematic coupling to the center node. The disk is pin-joined to the center node and can spin freely about that point. The rotation, however, is not coupled.
