For complex symmetric models, the application's multistage cyclic symmetry capability enables you to combine two or more independent cyclically symmetric systems with different sector counts. The purpose of symmetry is to reduce calculations times and disk and memory requirements. Multistage uses the existing symmetry capabilities to simplify the calculation process but adds multiple regions of symmetry. In doing so, the multistage feature incorporates:
Cyclic Region or Pre-Mesh Cyclic Region: This object specifies the symmetric region.
Stage: This object defines each of the bodies corresponding to a given cyclic component.
Interstage: This object specifies the connections between each Stage of the multistage analysis.
Use the procedure below to create a multistage cyclic symmetry analysis. More information and example problems can be found at the following links:
For an overview of the general procedure to reduce model size and computational cost in models with symmetry, see Symmetry Workflow in Mechanical.
For a detailed discussion and underlying theory, see Multistage Cyclic Symmetry Analysis Guide.
For tutorials that explain in detail the procedure for setting up a multistage cyclic symmetry analysis in the Mechanical Application, see
For more example problems that show the multistage cyclic symmetry work flow solved in Mechanical APDL, see Examples in the Multistage Cyclic Symmetry Analysis Guide.
The interstage displacement is the sum of contributions of many harmonic functions, only some of which significantly affect the response. For an example problem that demonstrates how to select relevant harmonic indices (HIs) to include in a multiharmonic multistage cyclic symmetry analysis for an accurate response, see Static Analysis of a 2-Stage Disk with Pinholes. To automate HI selection, use the multistage harmonic choice wizard (see Multistage Harmonic Choice Wizard in the Mechanical Add-ons Guide).
Important: This type of symmetry analysis does not support boundary conditions imported from an External Model system. If your simulation includes these (unsuppressed) boundary conditions, the Symmetry object becomes invalid.
Supported Analysis Types
Multistage analyses can be solved for the following analysis types:
Linear Perturbation Modal
Modal
Static Structural
Steady-State Thermal
Application
This procedure assumes that you have opened an appropriate model in Mechanical to create a multistage cyclic symmetry analysis:
Insert and specify the required number of Cyclic Region or Pre-Mesh Cyclic Region objects.
For each symmetric region, specify a Stage object:
Using the scoping properties, specify the entire body/bodies of each region. This region is associated with the Cyclic Region or Pre-Mesh Cyclic Region objects defined in the previous step. Only body selection is supported.
In the Cyclic Region property, specify the Cyclic Region or Pre-Mesh Cyclic Region corresponding to your body selections.
To define the connection between stages, you must specify an Interstage object. Under the Connections folder, insert an Interstage object and scope it to the two faces (Source and Target properties) that connect the previously defined stages. Only face selection is supported.
Note: Ansys recommends that you modify the mesh of the connection so that each side uses quadratic elements that are preferably the same type and size.
Setup environment and perform a solution.
Note: This analysis application supports the use of the following imported loads:
Temperature and Convection Coefficient for Steady-State Thermal analyses.
Body Temperature and Pressure for Static Structural analyses.
Limitation: Note the following:
Nodes located on the cyclic symmetry axis are not supported.
If you have a result object selected, certain mesh-based features are not available, including mesh selection filters (nodes, elements, and element faces), as well as the ability to display a Node ID in the probe label.