CECYCMS

CECYCMS, CycLowNod, CycHighNod, --, KMAP, TOLER, --, KPRINT, UsrNMap
Generates the constraint equations for a multistage cyclic symmetry analysis.

PREP7: Constraint Equations

SOLUTION: Dynamic Options

CycLowNod

The name of a component for the nodes located on the low angle edge of the sector (up to 240 characters enclosed in single quotes).

The sector is that of the current stage (Sname) specified with MSOPT,NEW,Sname or MSOPT,MODIFY,Sname. If blank and if the array parameter of edge node pairs does not exist (no user-defined or default for UsrNMap), the default component name is ‘_Sname_CYCLOW_NOD’.

CycHighNod

The name of a component for the nodes located on the high angle edge of the sector (up to 240 characters enclosed in single quotes).

--

Unused field.

KMAP

Option to use mapping when creating cyclic symmetry constraint equations. This option is ignored if you specify UsrNMap.

ON	—	Use mapping to relate low and high sector boundary DOFs when applying cyclic symmetry constraint equations.
OFF	—	Use matching node pairs from low and high sector boundaries to apply cyclic symmetry constraint equations (default).

TOLER

Tolerance for determining if one node on the low edge boundary matches the corresponding node on the high edge boundary after the nodes are rotated.

If positive	—	`TOLER` is absolute (length units, defaults to 1e-4). If the distance of the nodes is smaller than this absolute tolerance, the nodes are matched.
If negative	—	`TOLER` is relative. Considering the diagonal of an imaginary box enclosing the model, `TOLER` is a fraction of the length of that diagonal. Nodes within the relative tolerance are matched.

--

Unused field.

KPRINT

Option to print the table of matched nodes (KMAP = OFF) or mapped nodes and elements (KMAP = ON).

0	—	Do not print the table (default).
1	—	Print the table. If edge nodes are mapped (`KMAP` = ON) and a high edge node is matching a low edge node, the third column labeled "MAPPED" lists the node number. (See Snippets of Table Printed with `KPRINT` = 1 on CECYCMS ).

UsrNMap

Option for matching node pairs between low and high edges.

Input the name of an existing array parameter or a numerical key:

<name>

—

Name of a user-defined array parameter that specifies the matching node pairs. The node pairs in the parameter may be input in any order, but the low edge node must be the first entry in each pair. (See Example: CECYCMS with a User-defined Array Parameter for UsrNMap.)

0 (or blank)

—

If the default array parameter named _Sname_CYCNODPAIR already exists, it is used to specify the matching node pairs (default).

If this array parameter does not exist, nodes are paired automatically, and the array parameter named _Sname_CYCNODPAIR is created.

—

Nodes are paired automatically, and the array parameter named _Sname_CYCNODPAIR is created. If it exists, it is deleted and re-created.

-1

—

Nodes are paired automatically without creating or using an array parameter.

Notes

CECYCMS, CEIMS, and MSOPT are commands used in a multistage cyclic symmetry analysis.

If edge node pairs are matched (KMAP = OFF) and an array parameter is not specified for UsrNMap, components are used for the cyclic edge nodes. You must specify those components using the CM command and ensure that they contain base sector nodes only. See Building the Model for a more detailed discussion and Example Usage for examples demonstrating the use of CECYCMS in multistage cyclic symmetry analyses.

Snippets of Table Printed with KPRINT = 1 on CECYCMS —

If KMAP = OFF, matched nodes are printed:

   *****  CECYCMS - NODE PAIRS  ***** 
             nLow =       305 nHigh =       293 
             nLow =       477 nHigh =       471 
             nLow =       478 nHigh =       472 
             nLow =       479 nHigh =       473 
             nLow =       480 nHigh =       474 
             nLow =       481 nHigh =       475 
             nLow =       482 nHigh =       476 
             nLow =       279 nHigh =       270 
             nLow =       601 nHigh =       615

If KMAP = ON, matched mapped nodes and elements are printed:

         ********* MAPPED NODES AND ELEMENTS ********* 
                    NODE    ELEMENT    MATCHED NODE 
                    262        481          271 
                    263        487          272 
                    264        493          273 
                    265        499          274 
                    266        505          275 
                    267        511          276 
                    268        517          277 
                    269        523          278

Example: CECYCMS with a User-defined Array Parameter for UsrNmap —

*DIM,MYMAP,ARRAY,2,10          ! specifying 10 low-high edge node pairs
*set,mymap(1, 1), 107, 108     ! low node 107 <> high node 108
*set,mymap(1, 2), 147, 211     ! low node 147 <> high node 211
…
CECYCMS,,, ,,, ,,MYMAP

Example Usage

Example: Static Analysis of a Compressor Model with 4 Axial Stages Without a Duplicate Sector

Example: Linear Perturbation Modal Analysis of a Simplified Model with 2 Axial Stages and a Non-planar Interstage Boundary

Example: Modal Analysis of Turbomachinery Stage Modeled as 2 Radial Stages with Offset Cyclic Edge Starting Points

Example: Mutistage Multiharmonic Modal Analysis of a Hollow Cylinder Modeled Using 2 Stages

Example: Multiharmonic Linear Perturbation Modal Analysis of a Simplified Model with 3 Axial Stages

Menu Paths

This command cannot be accessed from a menu.