Easiest way to connect volumes

[JeroenDevos]

Hi,

by importing an assembly CAD file, Ansys recognizes the different volumes. I need to connect these volumes to perform a modal analysis on it. By doing this, I want to take into account the physical properties of the connection (bolt, guideway,...). Can anybody tell me what's the easiest way to do this. The Ansys help file mentions contactpair wizard, contact elements, use of combination elements (spring damper),...
I'm a bit lost in the number of the possibilities and don't really get what's the best way to have a realistic model.

Thanks in advance,
Jeroen

 

[meshparts]

Contact elements wont work, since they request nonlinear analysis and the modal analysis is a linear one.

I would use the combin elements, but this depends on the problem you want to solve...

Regards,
Alex

 

[JeroenDevos]

Hi,
thanks for the reaction Alex. My problem consists of the dynamic verification of a milling machine.
Can you give me some more specific information about how to use these combin elements?
thanks in advance,
Jeroen

 

[Stringmaker]

Jeroen, the best way to connect the two is to have a continuous mesh between them and use the AGLUE or NUMMRG commands. If this is not possible constraint equations (see CEINTF command) or contact elements will do the trick. In a dynamic analysis contact regions maintain their initial values and do not update due to the nature of the analysis. If you really want to use contact elements I'd recommend the MPC keyoption.

Good luck,
-Brian

 

[meshparts]

I often use combin14 Elements to define 1D stiffness elements. The following code defines three combin14 element types for the 3 cartesian directions

et,1,combin14,,1 ! x direction
et,2,combin14,,2 ! y direction
et,3,combin14,,3 ! z direction

r,1,...
r,2,...
r,3,...

See more details about combin14 in the Ansys Help.

Regards,
Alex