Moment Reaction probe with Large deformation

[Tom Ber]

Hi, 

I would like to read the reaction moment probe from the contact in a large displacement analysis. When I use the summation method: orientation system or centroid, the moment is read relative to the undisplaced centroid of the contact. I need the summation point to be at the centroid of the displaced contact. Is there any way to do this automatically? The only solution I have found is to move the coordinate system exactly by the value the geometry moves, but this is too labor-intensive to do for many contacts and many timesteps.

 

When the summation point does not move with the mesh, this results in a false reading of the moments. 

 

[dlooman]

Does specifying a node number on the APDL SPOINT command update the location to compute the moment about?

[Tom Ber]

Hi dlooman,

Thanks for your reply but I don't understand what exactly you mean. Could you please clarify it further?

could you give me some example of apdl code that I could use?

 

[dlooman]

Assuming you know the x,y,z location of the centroid and have a named selection for the nodes on the surface the commands would be:

 

cmsel,s,named_selection

spoint,node(x,y,z) 

fsum

allsel