Question:
It is not possible to design a SHAPE‑THIN cross-section due to invalid symmetry. What is the cause and how can I fix it?
Answer:
RF‑/ALUMINUM checks the symmetry of general cross-sections and compares them with the SHAPE‑THIN evaluation when activating the "Determine symmetry by module and compare with SHAPE‑THIN definition" check box (Image 01).
If the two methods provide different results, the corresponding error message appears (Image 02).
Usually, there are small inaccuracies in the SHAPE‑THIN cross-section. Thus, the cross-section Sec‑1.du9 shown in Image 03 is not absolutely symmetrical to the Z‑axis: The Z‑coordinates of Node 1 and Node 4 as well as Node 55 and Node 60 do not match in the second decimal place.
SHAPE‑THIN classifies the cross-section as asymmetrical, but RF‑/ALUMINUM as monosymmetric to the z‑axis, so the error message shown in Image 02 appears.
The SHAPE‑THIN cross-section should be checked for symmetry. When modeling in SHAPE‑THIN, it is useful to display only one side of the cross-section and create the other half by mirroring. This is also shown in the video.