Plot of reaction force makes no sense

Altair Forum User

good afternoon,

In my model today I have a cantilever beam to which I attach a string. The beam is fixed at one side. The free end of the string is pulled down by applying an SPC with the according nodal displacement.

I then try to plot the reaction force at the end of the string vs its displacement and only receive a zigZag line. The calculation is done with a non linear Geometry option because the resultant deflection of the beam is quite large (the material is still elastic yet).

I don't know wether it works with the file attachement but I try to attach a screeshot of the result.

On the other hand I thouhgt I might as well sum up all the vertical reaction forces at the fixed end of the beam but I couln't find a way to add them all up and plot the sum of the reaction forces vs string displacement. Is there such a function?

 

Would appreciate any help

 

thanks

 

Rainer

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Altair Forum User

Hi Rainer,

 

Have you tried to output the same SPCFORCE with NLSTAT analysis?

 

if not can you give it a try and check if the SPCF matches with NLSTAT results?

 

The best way to sum up the reaction force is to use the output file and use excel to sum the SPCF from the .out file.

Altair Forum User

hi Prakash,

I have tried the output with NLSTAT but to my understanding I will then only receive the result at the end of calculation. At least in the plot I get only a single point as result, not a line

 

Do I really find the results in the .out file? I only get a summation of applied forces and reaction forces an this is ideally zero.

 

regards

 

Rainer

Altair Forum User

Hi Rainer,

 

Sorry for a late reply.

 

Can you output SPCF with type as OPTI?

 

This will write a .spcf file in the working directory with reaction force and moment values in all three components.