CYSYM

Bulk Data Entry Specifies the number of segments, in a cyclic symmetry analysis.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
CYSYM	NSEG

Example

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
CYSYM	12

Definitions

Field	Contents	SI Unit Example
NSEG	Number of segments. No default (Integer > 1)

Comments

1. CYSYM and CYJOIN Bulk Data Entries are required in cyclic symmetry analysis.
2. Supported analysis types include linear static (STATIC), normal mode (MODES) and implicit nonlinear (NLSTAT & NL-DTRAN) analyses, and prestressed analyses are supported with STATSUB(PRELOAD).
3. For normal mode analysis, currently only Lanczos (EIGRL) and Lapack-based dense (EIGRD) solvers are supported. Note that field 4, ND, on both cards defines the number of roots desired for each harmonic in a cyclic symmetry modal analysis.
4. Linear static and normal mode cyclic symmetry analyses can simulate non-cyclic symmetric behaviors (deformation and mode shapes, respectively), and this sets it apart from analyses which use periodic boundary conditions. Non-cyclic symmetric behaviors are not supported for prestressing subcases in prestressed analysis due to theoretical restrictions. However, the subsequent prestressed subcase can have non-cyclic symmetry. Nonlinear analyses do not support non-cyclic symmetric behaviors.
5. SPC and MPC references in the subcase section are required to be consistent for all subcases in cyclic symmetry analysis.
6. The modeled segment is defined as the basic segment with index of 1. The rest of the segments are numbered following the right-hand screw rule, where the thumb points in the positive direction of the axis and the segment indices are defined sequentially in the counter clockwise order. Figure 1