Separate structure_Tubes + Beams + Sheet piling

[Anonymous]

Hello,

I'm modeling a sheet piling supported on several tubes through beams.

I find the error "Separate structure". I used the offset option for the beams, and Autocad to determine the exact place of the panels.

I've thought about using Rigid links, but I don't see how to use them in this case. 

Could you please help me?

Thanks in advance 

[Rafacascudo]

If you want to use offsets , You should keep your panels in their exact position and your beams and columms should be modelled centered on the panels planes. Only then you should apply the bar offsets for beam and columms" moving" them to their real position.

Right now , in the model you sent ,panels are completely separated from the rest of the structure

But I would use rigid links

[Anonymous]

Hi and thanks for your responsiveness, 

I've just modeled a simplified structure with only 1 panel, 2 beams and 1 tube. 

I designed all the elements in the same plane and applied the "offsets" for the pile and the beams. 

For connecting the beams to the tube, I divided the beams in two parts, to generate an intermediate node in each of them.

Then I applied the rigid links between these intermediate nodes and the extreme nodes of the tube. 

I've attached some pictures to show several results. 

Please have some questions:

• Picture 2: 
  • Is it necessary to use the rigid links to connect the beams with the tube, or are they already connected because of the offsets? 
  • In the red circles, why is the IPE crossing the tube? Is the IPE profile supported on the pile?
• Picture 5:
  • Why is this deformation going upward (upper beam) and downward (bottom beam)? 
• If we don't use "offsets", how could we connect the beams to the panel? Should we divide the beams in many parts to connect them to the mesh panel through rigid links?

Many thanks!

[Rafacascudo · Accepted solution]

Is it necessary to use the rigid links to connect the beams with the tube, or are they already connected because of the offsets? 

If you use offsets it´s not even necessary to divide the beam in 2 parts.If bars cross each other in the same plane and this below is marked on structure model(which is by default) , then Robot will automatically create an "invisible" calculation node

In the red circles, why is the IPE crossing the tube? Is the IPE profile supported on the pile?

In the model you sent , Offsets are active(defined) and rigid links are incomplete(no slave nodes defined) , so they are useless . So ,yes Ipe profile is supported by pile.

Why is this deformation going upward (upper beam) and downward (bottom beam)?

It seems "exact deformation for bars" is a  different from what shows mesh displacement map

. I don´t know exactly why( maybe official support?). I would go with mesh displacements. Also check node displacement table. Uz(vertical) displacement shows only 3mm for both upper and bottom nodes

If we don't use "offsets", how could we connect the beams to the panel? Should we divide the beams in many parts to connect them to the mesh panel through rigid links?

Yes , divide(create nodes along, don´t need to divide the bar in pieces) the bars according to your mesh size . Then copy these nodes to the panel plane. Use full rigid links to connect them. Mesh the panel

You can use Romanich excelent Spider tool to make your job easier with the many rigid links. Search the forum for it

PS- Offsets are treated as rigid links internally

[Anonymous]

That was really helpful!

Thanks a lot!! 😉