Learning Forum

[simone.doniselli]

Hi everyone!

I'm trying to emulate the presence of a solid body (a precision stage in a measurement system) both in structural (thermal condition) and modal analysis. 
My idea is to associate a remote point in the COG of the body I'm emulating and scoping it to the surfaces the body is jointed to. A point mass is then associated with this remote point to embody its inertial properties.
The remote point behavior is set to "beam" so that the material's thermal properties can be selected.
As an example, I set up this scenario: 

However, the real expected deformation should be about 13.2µm instead of the resulting 6.8µm, as well as the stress should be null:

           

Hence I suppose that the constraint equations of the remote point are not properly defined.

I already tried inserting an APDL command in the analysis using commands such as d, all, ux or ddele, all, ux etc but it didn't work.

Please help me fix this setup or suggest a better approach for my needs. 

Thank you, 
Simone

 

 

 

[dlooman]

I think the use of beam behavior could be causing the problem.  Creating hundreds of beams between the remote point and the scoped surfaces could be ruining the solution.  If you use deformable behavior you will get a heat and force balance between the point mass and the surfaces.