question on assing "area load" 2

[hualiong]

i couldn't figure out the difference between "Uniform (shell) and "Uniform to frame (shell) when I use the shell element and assign the load to a certain area? Does someone understand how to use that and interperet a little more? Apprecaited for your thoughts.

Thank you.

 

[Skicat]

Uniform sheel area loads are distributed at the mesh points. Uniform shell to frame loads are distributed to the frame elements

 

[lisica]

Hi,
can you tell as an example where I can see the difference between that assigns? When should we use the first one and when the second one?

thx

 

[ugoveri]

The uniform to framel (shell) load assignment, is used to substitute the manual introduction of line loads on frames. It doesn't take into account the rigidity of the shell itself for the load distribution.

Imagine you have a floor constituted of steel beams and one way slabs. You can (i) assign the loads as line loads taking account for the area of influence of each beam; or (ii) use the uniform to frame load introduction which will do it for you directly. It can also be done for 2 way slabs.

Of course if you use the regular uniform load application part of the load will also go for your beams, but since it is dependent of the mesh and of the beam and shell relative rigidity, part of the load is transfered directly to the end nodes of the beams. In the end you will not get the exact moment and shear as if was obtained by area of influence.