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rotate a volume around a centre

rotate a volume around a centre

rotate a volume around a centre

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

RE: rotate a volume around a centre

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

RE: rotate a volume around a centre

(OP)
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

RE: rotate a volume around a centre

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.

RE: rotate a volume around a centre

(OP)
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)

RE: rotate a volume around a centre

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

RE: rotate a volume around a centre

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

RE: rotate a volume around a centre

(OP)
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

RE: rotate a volume around a centre

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

Regards

RE: rotate a volume around a centre

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

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