Learning Forum

[heyboyy]

Hello everyone, Im trying to perform a cyclic symmetric analysis for my thesis. I use symmetry region (cyclic) and cpcyc command both and when I do that I just see harmonic index 0 results. However, if I delete cpcyc command I see other harmonic index values. Could you help me about it ?

Thank you.

[wrbulat]

Hello
CPCYC defines coupled degree of freedom sets between corresponding pairs of nodes on the boundaries straddling the periodic sector. This forces all three components of displacement (radial, circumferential, and axial) on the surfaces to be identical at corresponding locations on those surfaces. After reviewing the Help section below, I think the implication is that this forces the calculated modes (presumably you're doing a modal analysis) to only be those having harmonic index = 0.

Another legacy command (found in the Help Feature Archive) associated with the older, now undocumented cyclic symmetry analysis method we used to have is CECYC, which writes constraint equations between corresponding pairs of node on the surfaces. Constraint equations are more general than coupled degree of freedom sets. The command allows manual specification of the harmonic index that calculated mode shapes will be limited to. I forget... I think CECYC is used in the context of a model in which the cyclic sector has already been duplicated (e.g., via CYCLIC).

Best Bill