Learning Forum

[DanWood93]

Hi, 

How does one use cyclic symmetry in a 2D model? It only seems possible for 3D?

[Rob]

Which solver are you using? 

[DanWood93]

I am using workbench the mechanical solver version 18.1

[Rob]

 We'll need to wait for a Mech expert: I don't know how it's defined in that solver. 

As an aside, why are you using R18.1 over 2019R3? 

[peteroznewman]

Dan,

Please describe in detail what you want to model. Below is the image you attached above.

[DanWood93]

Hi, 

I am trying to model the stress in a rotor sleeve. The stress is developed from an interference fit between the sleeve inner surface and magnet outer. I want to look at the hoop and radial stress in the sleeve when it is a) stationary and b) rotating at high speed. In doing so i want to develop a 2D model of the shaft-magnet-sleeve components, to which i modelled a 1/4 of, as per image i initially supplied, however, when trying to apply a symmetry condition to the boundaries of the model, there is no such option to apply a cyclic symmetry (image attached), how does one then apply the boundary conditions?

[peteroznewman]

Save the 3D geometry into a SpaceClaim .scdoc file. Start a new Static Structural. In Workbench, set the Geometry Type to 2D.

Here is a Tutorial on an Axisymmetric model.

In SpaceClaim, open the geometry file, rotate the 3D solid geometry so the axis of symmetry is along the Y-axis. Split the body in the XY plane, then repeat in the YZ plane. Select all the faces in the XY plane on the +X side and Copy then Paste. Delete all the solids. These surfaces are a radial slice. When you bring them into Mechanical, set the Analysis type to Axisymmetric.  Now results for the X-component are Radial Stress and the Y-component are Hoop Stress.

[DanWood93]

Hi, 

I am having license problems with SpaceClaim. However, I have done the following can you please advise on this. 

Firstly, added a symmetry region on the edge along the Y-axis and with a symmetry normal in the X-axis, and vice versa with the edge along the Y-axis.

Secondly, added a displacement on the x-axis free to displace on the x but not on the y, and vice versa. 

I was instructed to use an APDL snippet since the cyclic symmetry option is not available with the GUI 18.1. Here is the APDL, however, i am an electrical engineer and don't actually how to use this snippet. If you could help regarding this it would be great.

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v201/en/ans_cmd/Hlp_C_CYCLIC.html

[peteroznewman]

You don't need the displacements if you defined Symmetry Regions, they are both creating the same code, so there is no harm, it's just redundant.

You don't need cyclic symmetry in the mesh.

You should create a cylindrical coordinate system to plot the results.