HARMONICS

HARMONICS = 26
SET, 26, MODE
+, 0, 1, 2, 6, 10

HARMONICS = 26
SET 26 = 0, 1, 2, 6, 10

1. When the HARMONICS I/O Option is not present, HARMONICS=ALL will be set by default in cyclic symmetry analysis.
2. The SET definition referenced by HARMONICS should be a set of TYPE = MODE.
3. The harmonic indices are supposed to be non-negative and must be no greater than (NSEG is defined in the CYSYM Bulk Data Entry).

   If NSEG is odd:

   $$\left(\frac{NSEG-1}{2}\right)$$

   If NSEG is even:

   $$\left(\frac{NSEG}{2}\right)$$

4. Further remarks regarding different harmonic options for different subcase types are summarized in the table.

   Subcase Type	Non-cyclic Symmetric Behavior	Cyclic Symmetric Behaviour*
   Linear Static	Cyclic symmetry analysis can solve for non-cyclic symmetric deformation if non-cyclic symmetric loadings (including non-cyclic symmetric SPCD) exist in the input file. The result is a linear superposition of all the requested harmonic solutions. When all the necessary harmonics are requested, cyclic symmetry linear static analysis is capable of generating deformation identical to a regular linear static analysis which has all the segments of the structure being modelled; therefore, HARMONICS=ALL is usually recommended. In general, harmonics with lower indices contribute more to the result of in a linear static cyclic symmetry analysis, and removing some harmonics may lead to loss in accuracy.	If there is no non-cyclic symmetric loading (including non-cyclic symmetric SPCD), all the harmonics vanish except the 0th harmonic, which leads to cyclic symmetric deformation.
   Normal Mode	Each harmonic solves for a series of modal shapes of a certain pattern and the result is a collection of modes calculated from the requested harmonic solutions. When all the necessary harmonics are requested, cyclic symmetry normal mode analysis is capable of generating a same number of modes identical to a regular normal mode analysis which has all the segments of the structure being modelled. Removing a certain harmonic index h from the set referenced by HARMONICS would result in the absence in the corresponding mode shapes with h nodal diameters.	The 0th harmonic corresponds to mode shapes with cyclic symmetric mode shapes, that is, no nodal diameter.
   Nonlinear Static, Nonlinear Transient	N/A	Only the 0th harmonic (as in, completely cyclic symmetric behaviour) is allowed due to theoretical restrictions.
   Preloading/Preloaded Subcase in Prestressed Analyses	Subsequent preloaded subcase can have non-cyclic symmetric deformation or modes.	Preloading must be completely cyclic symmetric due to theoretical restrictions.