Learning Forum

[pedrocarneiro]

I am a little bit confused about fsum and nforce commands.
What are the differences between each other and in what situations shall they be used?
For example, if both commands are applied to the same node and elements the results should be equal?

Thanks

[Erik Kostson]

Hi

They are very similar.

Some differences (e.g., coordinate system in which to perform for summation - fsum has this option but not nforce) can be seen in the help manu l (search for these commands).

Finally as it says there (help manual) the nforce will print the nodal force (for each node that is selected) and then in the end do a summation of these forces just like what FSUM does. So FSUM just does the summation but does not print all individual force as NFORCE does. So one can then say that nforce prints individual forces for each nodes and does a FSUM in the end - this is mentioned in the help manual (just search for these there).

Erik

[pedrocarneiro]

Dear Ekoston Thanks for the answer.
I understand the definitions and the differences.
But i am trying to do a very simple case of double simple supported beam and if i select only one node and one element the results of fsum and nforce commands should be the same right?

[Erik Kostson]

Please read through what I wrote above, we can not over generalise this to every single case, but what we said is:
'So one can then say that nforce prints individual forces for each nodes and does a FSUM in the end (in the global system only - FSUM command can do this in a different coordinate system) - this is mentioned in the help manual (just search for these there).'
I would say try it out and see how this works and what they print out.

All the best

Erik