rotate a volume around a centre 1

[jiligeo]

Dear friends, how can I rotate a volume around a defined centre in Ansys?

 

[meshparts]

Hello,

You can use the command VGEN. But first define a local coordinate system (polar or cylindrical) using the command LOCAL.

VGEN works in the active coordinate system. If the system is cylindrical, then X is the radius, Y the angle.

Regards,
Alex

 

[jiligeo]

Dear Alex thanks a lot for your answer and sorry for late reply. Actually I want to rotate a volume and its corresponding (elements, nodes …) around a centre. I have found Vtran command for this purpose.
My new problem is: how can I define a local coordinate system that makes a rotation on a special centre after transporting a volume to it?
I am modelling a hip joint and I want to rotate femur bone around pelvic. The volumes are created at another program with iges format and they are imported to Ansys.

Regards
Jalil

 

[Stringmaker]

If you truly want to create a volume then by definition you would rotate an area about an axis. You cannot rotate a volue to get a volume. VTRAN is simply to copy a volume from the active coordinate system to the same relative position in another defined coordinate system. It's used to move or copy objects.

 

[jiligeo]

Dear Stringmaker's, thank you for your reply. I have created the volumes in another program and now I want only to rotate one of them around a special point (femur in acetablum). I do not want to create new volume.
As the rotation point is not at the origin of coordinate system, every rotation makes a transformation at this point too.
My problem is: how can I define a local coordinate system that makes a rotation on a special centre after transporting a volume to it? (without changing the position of this point)

 

[Stringmaker]

Jalil,
You cannot rotate a volume to produce a volume as the output. You can rotate an area however. To do so:

LOCAL !define local CS, should be cylindrical
VEXT !extrudes (or rotates in this case) areas into volumes

 

[cbrn]

Hi,
if I understand well, you have plenty of ways to define a CSYS where you want. See LOCAL, CSWPLA, CS, CLOCAL, CSKP.
If you define it as "cylindrical", the move/copy transformation will then be trivial because the Y-coordinate is the rotation (in degrees by default).

Regards

 

[jiligeo]

Dear friends, I think, I could not explain my problem exactly.
I have two volumes with Iges format, which is imported to Ansys. They are created in Cartesian coordinate system in Geomagic program. Now I want to rotate one of them (after meshing) around a point in Ansys classic. (The point is not at origin)
I do not want to copy a new volume. I just want to analyse a joint at different positions.
Thank you very much for your answers.

Regards
Jalil

 

[cbrn]

Fast way:
define a CSYS at the rotation point,
VGEN a rotated copy of the volume+mesh,
delete or unselect the original one.

Regards

 

[Stringmaker]

To add to what cbrn said you can do this in two commands:

vsel !select volumes
vgen,2,all,,,,,,,0,1

Take a look at the VGEN command in the help. Once you have your cylindrical coordinate system defined this should take less than 30 seconds to do.

-Brian