History Output - Total forces not saved to local CS

Bug Reports
1

For the History Output RF, the nodal forces are saved correctly to the local CS but the total forces are not.
Could this be changed or is there a limitation?

Thanks

Tested with v2.1.6
Test.pmx (242.9 KB)

HO
HO1537Ă—700 72 KB

2

CalculiX computes the total force, and PrePoMax only shows the result. So, this might be a CalculiX issue.

You can try creating a user-transformed reaction force field output and then use equation history outputs to sum the reaction forces in each direction.

Edit: I see the field output is ok. So, you don’t need the first step of transforming the field output. You can actually use the history output equation with a filter to get the resulting components. The equation for the first direction is simply: [TOTAL_FORCE.RF1] and use filter Sum → Columns.

1 Like
3

Hmm okay, so the total Force is always saved in the global CS. Then i would suggest to add a hint to avoid misunderstandings:

tf
tf336Ă—560 9.28 KB

To get the total forces in the local CS (Global = no), this equation works =[NH_OUTPUT-1.FORCES.RF1] → Sum → Rows. I always get the error “Parameter was not defined” when trying to enter =[NH_OUTPUT-1.TOTAL_FORCE.RF1] or just [TOTAL_FORCE.RF1].

4

Which version are you using? Can you try it in the newest version?

5

Version 2.1.6

tf2
tf21418Ă—529 45.8 KB

6

Aha, looking at the image, I think the problem is that the Total force in the results tree has a space character.

I will look at the code to see what happens, but the correct equation would be:

=[NH_OUTPUT-1.TOTAL FORCE.RF1]

***Edit

The proposed equation works for me. Maybe I should consider changing the name TOTAL FORCE to TOTAL_FORCE (and other names with spaces) in the future.

1 Like
7

I am not sure. I would expect it to be in the local coordinate system. Maybe the problem is that different nodes could have different coordinate systems.

8

Okay I think the answer is clearly given in Chapter 7.98 - Node print:

“The parameter TOTALS only applies to external forces… Notice that the sum is always written in the global rectangular system, irrespective of the value of the GLOBAL parameter.”

Because it’s not very intuitive, i would appreciate it if the 2nd part would also be added to the comment:

t

1 Like
9

I will add the notice to the GUI.

1 Like
10

I am closing this bug report.